JP2015219021A - Timepiece and satellite signal reception method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a timepiece capable of reducing average search time of position information satellites and of reducing power consumption, and further to provide a satellite signal reception method of the timepiece.SOLUTION: An electronic timepiece 1 comprises: reception means (a reception section 18); reception control means; timing means (RTC 21); and satellite storage means (a satellite storage section 23) storing satellite numbers and reception execution time of position information satellites captured by the reception means (reception section 18). The reception control means has: a fixed search mode where the position information satellites are searched in an order set beforehand in the reception means (reception section 18); and a priority search mode where the position information satellite of the satellite number stored in the satellite storage means (satellite storage section 23) by the reception means (reception section 18) is preferentially searched. The reception control means selects one of the fixed search mode and the priority search mode in response to elapsed time from past reception execution time stored in the satellite storage means (satellite storage section 23) and causes the position information satellites to be searched when executing reception processing.

Description

  The present invention relates to a timepiece having a function of receiving a satellite signal from a position information satellite such as a GPS satellite and a satellite signal receiving method of the timepiece.

An electronic timepiece that receives a satellite signal transmitted from a position information satellite such as a GPS (Global Positioning System) satellite and corrects the time has been proposed (for example, see Patent Document 1).
The electronic timepiece of Patent Document 1 pays attention to the fact that the position information satellite is located at approximately the same place at the same time every day, stores the reception history of the position information satellite together with the reception time, The position information satellite corresponding to the time is selected and reception processing is performed. For this reason, since it is only necessary to search for the selected position information satellite, the search time can be shortened and the power consumption can be reduced.

Japanese Patent Laid-Open No. 10-10251

  However, since the electronic timepiece of Patent Document 1 creates a reception history for each time (every 8 minutes), it is necessary to search for a position information satellite every 8 minutes in the installation stage (initial stage) of the electronic timepiece. is there. For this reason, the number of searches for position information satellites (satellite signal reception) increases, and power consumption increases. In addition, since the amount of information to be stored increases, the scale of the memory circuit (memory capacity) increases, and from the viewpoint of power consumption and memory capacity, it cannot be applied to a portable electronic timepiece such as a wristwatch.

  An object of the present invention is to provide a timepiece and a timepiece satellite signal receiving method capable of shortening an average search time of a position information satellite and reducing power consumption.

  The timepiece of the present invention captures a position information satellite, receives a satellite signal transmitted from the captured position information satellite, a reception control means for controlling the reception means to perform a reception process, and a time measurement. Time measuring means, and satellite storage means for storing the satellite number of the position information satellite captured by the receiving means and the reception execution time at which the reception processing is executed, and the reception control means is provided in advance in the receiving means. A fixed search mode for searching for the position information satellites in a predetermined order; and a priority search mode for causing the receiving means to search for a position information satellite with the satellite number stored in the satellite storage means preferentially. When the reception unit executes the reception process, the fixed search mode and the priority are selected according to the elapsed time from the previous reception execution time stored in the satellite storage unit. Selects one of the search modes, characterized in that to search the position information satellite.

Here, the past reception execution time stored in the satellite storage means is, for example, the previous reception execution time when the reception execution time for one time can be stored in the satellite storage means, and is 3 in the satellite storage means. When the reception execution time for the number of times can be stored, for example, the reception execution time of the previous time, the previous time, and the previous time (three times). In general, a position information satellite (for example, a GPS satellite) orbits the earth in approximately 12 hours, and the earth also rotates. Therefore, position information at the same place at the same time (for example, 24 hours later). If a satellite is searched, there is a high possibility that the same position information satellite as the position information satellite acquired in the past (for example, the previous time) can be acquired. The search for the position information satellite in the priority search mode is, for example, searching for the position information satellite of the satellite number stored in the satellite storage means first (priority search) and then searching for other position information satellites. Say. Furthermore, the reception execution time may be any of reception start time, position information satellite capture time, satellite signal reception time, and the like. This is because the same position information satellite can be captured after an elapsed time (for example, 24 hours) at any of these times.
For this reason, for example, when searching for the position information satellite of the satellite number stored in the satellite storage means in the priority search mode when 24 hours have elapsed from the time when the reception process was executed in the past, it moves to a different time zone region. If such a large movement is not performed, there is a high possibility that the position information satellite can be reliably captured at the priority search stage. This makes it possible to search for a position information satellite in a shorter time than to search for a position information satellite in a predetermined order, and to receive a satellite signal transmitted from the position information satellite.
On the other hand, when, for example, 12 hours have elapsed since the time when the reception process was executed in the past, when the position information satellite is searched for in the priority search mode, the position information satellite with the satellite number stored in the satellite storage means is located behind the earth. The position information satellite cannot be captured. That is, if the position information satellite with the satellite number stored in the satellite storage means is always preferentially searched, even the position information satellite that cannot be captured is preferentially searched, and unnecessary reception processing is executed. Will do. Therefore, if the position information satellite cannot be acquired at the priority search stage, it is necessary to search for the remaining position information satellites. As a result, it takes time to acquire the position information satellite and receive the satellite signal, and the consumption. Power increases. For example, in such a case, searching for a location information satellite in the fixed search mode for searching for a location information satellite in a predetermined order prevents the use of a prioritized search so that the location information satellite is captured earlier. It is highly possible.
In the present invention, the position information search mode is selected by selecting either the priority search mode or the fixed search mode according to the elapsed time from the reception execution time when the reception process is executed and stored together with the satellite number. A satellite is searched. Thereby, in any of the above cases, the mode for searching for the position information satellite is selected according to the elapsed time from the past reception execution time, and therefore, there is a high possibility that the position information satellite can be quickly captured. For this reason, the acquisition time of an average position information satellite can be shortened. Therefore, the search time for the position information satellite, that is, the reception time of the satellite signal can be shortened and the power consumption can be reduced.

In the timepiece according to the present invention, the reception control means may perform reception processing according to the priority search mode during scheduled reception processing that is activated when the time measured by the time measuring means reaches a preset reception time. Is preferably performed.
According to the present invention, since the reception process in the priority search mode is executed at the time of the scheduled reception process that operates at a preset time, the satellite storage means is used when the past (for example, the previous) scheduled reception process is executed. If the position information satellite with the satellite number stored in the search is searched, it is highly possible that the position information satellite can be captured. That is, in the case of such a regular reception process, a search for a position information satellite in the priority search mode can be performed to prevent a search for a useless position information satellite. Therefore, the search time for the position information satellite, that is, the reception time of the satellite signal can be shortened and the power consumption can be reduced.

  The timepiece according to the present invention includes an operation unit that executes the reception process by the reception unit, and an elapsed time from the reception execution time of 24 hours × n (n is 1 or more) when the operation unit is operated. A determination unit that determines whether or not the value is within a predetermined range from an integer), and the reception control unit uses the determination unit to determine whether the elapsed time from the reception execution time is a predetermined value from the 24 hours × n. When it is determined to be within the range, it is preferable to execute the reception process in the priority search mode.

Here, the predetermined range can be exemplified by a range of 24 hours × n ± 2 hours, which is a range in which the position information satellite of the satellite number stored in the satellite storage means is highly likely to be captured.
For example, a reception process (hereinafter referred to as a manual reception process) executed by operating the operation means is not executed every day at the same time, unlike a scheduled reception executed at a preset time. For this reason, when the manual reception process is executed, if the position information satellite is always searched in the priority search mode, for example, the manual reception process is executed 12 hours after the previous reception process is executed. In addition, the position information satellite that is highly likely not to be received is searched with priority, and the power consumption increases.
On the other hand, according to the present invention, when the execution of the manual reception process is instructed, the elapsed time from the reception execution time stored in the satellite storage means is within a predetermined range from the 24-hour period (for example, 24 hours × If it is within the range of n ± 2 hours, reception processing in the priority search mode is executed. That is, if it is within the range of ± 2 hours from the 24-hour cycle, it is highly possible that the position information satellite with the satellite number stored in the satellite storage means can be captured. It is highly possible that the search for the position information satellite can be completed only by searching for the position information satellite).
On the other hand, when the execution time of the manual reception process is instructed, if the elapsed time from the reception execution time stored in the satellite storage means is not within the predetermined range from the 24-hour period, it is stored in the satellite storage means. Since it is unlikely that the satellite number position information satellite can be captured, the reception process in the fixed search mode is executed.
Therefore, even in the case of manual reception processing, it is possible to prevent a search for useless position information satellites, so that an average search time for position information satellites can be shortened and power consumption can be reduced.

  In the timepiece of the present invention, the satellite storage means includes a satellite number of the position information satellite acquired by a scheduled reception process that is activated when the time measured by the time measuring means reaches a preset reception time. A first storage area for storing a scheduled reception execution time when the scheduled reception process is executed, a satellite number of the position information satellite captured by a forced reception process that is a reception process other than the scheduled reception process, and A second storage area for storing a forced reception execution time when the forced reception process is executed, and an elapsed time from the scheduled reception execution time when the scheduled reception process is executed by the receiving unit. Is determined when the forced reception process is executed by the first determination means for determining whether or not is within a predetermined range from 24 hours × n (n is an integer equal to or greater than 1). Second determination means for determining whether or not an elapsed time from the reception execution time is within a predetermined range from the 24 hours × n, and the reception control means is configured to perform the fixed time by the first determination means. When it is determined that the elapsed time from the reception execution time is within a predetermined range from the 24 hours × n, or the elapsed time from the forced reception execution time is from the 24 hours × n by the second determination unit. When it is determined that it is within the predetermined range, it is preferable to execute the reception process in the priority search mode.

Here, as a forced reception process that is a reception process other than the regular reception process, a manual reception process in which a reception process is forcibly executed by an operation of an operation unit or the like, and a watch having a solar panel, An automatic light receiving process that is automatically executed when the solar panel is irradiated with light can be exemplified.
According to the present invention, the satellite storage means stores the first storage area in which the satellite number of the position information satellite captured by the scheduled reception process and the scheduled reception execution time are stored, and the position information satellite captured by the forced reception process. And a second storage area in which the satellite number and the forced reception execution time are stored, so that the satellite number and the reception execution time (the scheduled reception execution time and (Forced reception execution time) can be stored. Further, when the first determination means executes the scheduled reception process, it is determined whether the elapsed time from the scheduled reception execution time stored in the first storage area is within a predetermined range from the 24-hour period. As a result, when the scheduled reception process is executed, the reception process in the priority search mode can be executed with a very high probability, so that it is possible to prevent a search for useless position information satellites.
On the other hand, when the second determination means executes the forced reception process, it is determined whether or not the elapsed time from the forced reception execution time stored in the second storage area is within a predetermined range from the 24-hour period. Thus, for example, if the forced reception process is a light automatic timing reception process, there is a high possibility that the solar panel is irradiated with light at a fixed time every day, so the reception process in the priority search mode is executed with a high probability. it can. For this reason, it is possible to prevent a search for useless position information satellites in both the regular reception process and the forced reception process. Therefore, the average search time for the position information satellite can be shortened and the power consumption can be reduced.

  In the timepiece of the present invention, the second determination means stores the forced reception execution time stored in the second storage area and the first storage area when the forced reception processing is executed by the reception means. It is determined whether or not an elapsed time from the scheduled reception execution time is within a predetermined range from the 24 hours × n, and the reception control means uses the second determination means to determine the forced reception execution time and the When it is determined that the elapsed time from at least one of the scheduled reception execution times is within a predetermined range from the 24 hours × n, the satellite number stored in the storage area to be determined is used. It is preferable to execute the reception process in the priority search mode.

  According to the present invention, when the forced reception process is executed, it is determined whether the elapsed time from both the forced reception time and the scheduled reception time is within a predetermined range from the 24-hour period. That is, if any of the elapsed time from the scheduled reception time and the elapsed time from the forced reception time is within a predetermined range from the 24-hour period, the reception process in the priority search mode is executed. Therefore, the forced reception process in the priority search mode can be executed with higher probability than when only the elapsed time from only the forced reception time stored when the previous forced reception process is executed is determined. Therefore, it is possible to prevent a search for useless position information satellites, so that an average search time for position information satellites can be shortened and power consumption can be reduced.

  In the timepiece according to the present invention, the receiving means captures three or more position information satellites, receives satellite signals transmitted from the position information satellites, and acquires position information based on the satellite signals. Preferably, the reception control means causes the position information satellite to be searched in the fixed search mode when the positioning process by the positioning processing means is executed.

Here, the reception means acquires time information included in a satellite signal transmitted from at least one position information satellite, and performs time correction processing (hereinafter referred to as time measurement processing) to correct the time information. And positioning processing means for receiving a satellite signal transmitted from three or more position information satellites and executing processing that requires position information (hereinafter referred to as positioning processing).
When the timekeeping process is executed, the reception control means executes the reception process by selecting either the fixed search mode or the priority search mode according to the elapsed time from the time stored in the satellite storage means. To do. That is, in the time measurement process, it is sufficient that at least one position information satellite can be captured. Therefore, if one of the search for the position information satellite in the priority search mode and the search for the position information satellite in the fixed search mode is executed according to time. There is a high possibility that at least one position information satellite can be acquired in a short time. Thereby, in the time measurement process, if either the priority search mode or the fixed search mode is selected and the reception process is executed, it is possible to prevent a search for useless position information satellites.
On the other hand, when the positioning process is performed, there is a possibility that the user may be performed in a place (for example, a different country) different from the place where the user performed the satellite signal reception process last time. In such a case, even if a search for the position information satellite in the priority search mode is performed according to the time stored in the satellite storage means, the possibility that the same position information satellite can be searched is low. For this reason, in the present invention, in the positioning process, the search in the fixed search mode is always executed without selecting the priority search mode. As a result, since the satellite signal reception process in the priority search mode is not performed, it is possible to prevent a search for useless position information satellites.
Therefore, when performing any of the time measurement process and the positioning process, the search for useless position information satellites is prevented, so that the average search time for position information satellites can be shortened and the power consumption can be reduced. .

In the timepiece of the invention, it is preferable that the satellite storage unit stores satellite information of the position information satellite every time the reception process is executed.
Here, examples of the satellite information include a Doppler frequency and a received signal level (SNR: Signal to Noise Ratio). Further, in order to accurately receive the satellite signal transmitted from the position information satellite, the satellite signal is searched for each position information satellite in consideration of the Doppler frequency due to the movement of the position information satellite and the clock provided with the receiving means. It is necessary to determine the frequency.
According to the present invention, since satellite information (for example, Doppler frequency and SNR) is stored in the satellite storage means, for example, when there are a plurality of satellite numbers stored in the satellite storage means, the SNR is the satellite information. If stored, it is possible to set a priority order for searching for the position information satellites in order from the position information satellite having the highest probability of being captured based on the SNR. Further, if the Doppler frequency is stored as the satellite information stored in the satellite storage means, the frequency for searching the position information satellite can be set in advance based on the Doppler frequency. As a result, when a location information satellite is searched in the priority search mode, it is possible to search in order from the location information satellite with the highest search priority, and the frequency for searching for the location information satellite can be instantly set, so that it can be reliably performed in a short time. The position information satellite can be captured. Therefore, the average search time for the position information satellite can be shortened and the power consumption can be reduced.

  The timepiece satellite signal receiving method of the present invention includes a receiving means for capturing a position information satellite, receiving a satellite signal transmitted from the captured position information satellite, and a receiving control means for controlling the receiving means to perform a receiving process. And time measuring means for measuring time, and satellite storage means for storing the satellite number of the position information satellite captured by the receiving means and the reception execution time at which the reception processing is executed, the reception control means comprising: A fixed search mode in which the receiving means searches for the position information satellites in a predetermined order, and a priority search mode in which the receiving means preferentially searches for position information satellites of the satellite numbers stored in the satellite storage means. A satellite signal reception method for a timepiece comprising a past reception execution time stored in the satellite storage means when receiving a satellite signal transmitted from the position information satellite. Depending on the time elapsed al, the fixed search mode, characterized by searching for the positioning information satellite by selecting one of the first search mode.

  Also in the satellite signal receiving method of the timepiece of the present invention, the same operational effects as the timepiece can be obtained.

1 is a schematic diagram showing an electronic timepiece according to a first embodiment of the present invention. 1 is a schematic cross-sectional view of an electronic timepiece according to a first embodiment. The figure for demonstrating the structure of a navigation message. The block diagram which shows the main hardware constitutions inside the electronic timepiece which concerns on 1st Embodiment. The figure which shows the information regarding the positional information satellite memorize | stored in the memory | storage part of the electronic timepiece which concerns on 1st Embodiment. The figure which shows the structure of the control part of the electronic timepiece which concerns on 1st Embodiment. The figure which shows an example of the time slot | zone when a GPS satellite appears in the sky. The figure which shows an example of the change of the elevation angle of a GPS satellite. The flowchart which shows the procedure of the regular time measurement reception process of the electronic timepiece which concerns on 1st Embodiment. The flowchart which shows the procedure of the forced time reception process of the electronic timepiece which concerns on 1st Embodiment. The figure which shows the structure of the control part of the electronic timepiece which concerns on 2nd Embodiment of this invention. The flowchart which shows the procedure of the regular time reception process of the electronic timepiece which concerns on 2nd Embodiment of this invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
[Schematic configuration of GPS including electronic watch]
FIG. 1 is a schematic view showing an electronic timepiece 1 according to the first embodiment of the present invention. First, an outline of GPS in which the electronic timepiece 1 uses the radio wave as an external signal to obtain the current location information and time information will be described.

  The electronic timepiece 1 is a wristwatch that receives radio waves (satellite signals) from a GPS satellite 8 and corrects the internal time, and is a surface (hereinafter referred to as a surface) opposite to a surface that contacts the arm (hereinafter referred to as a back surface). Time). The GPS satellite 8 is a navigation satellite orbiting in a predetermined orbit above the earth, and transmits a navigation message superimposed on a 1.57542 GHz radio wave (L1 wave) to the ground. In the following description, the 1.57542 GHz radio wave on which the navigation message is superimposed is referred to as a satellite signal. The satellite signal is a right-handed circularly polarized wave.

  Currently, there are about 31 GPS satellites 8 (only four are shown in FIG. 1), and in order to identify which GPS satellite 8 the satellite signal is transmitted from, each GPS satellite 8 has C A peculiar pattern of 1023 chips (1 ms cycle) called a / A code (Coarse / Acquisition Code) is superimposed on the satellite signal. In the C / A code, each chip is either +1 or -1, and looks like a random pattern. Therefore, by correlating the satellite signal and the pattern of each C / A code, the C / A code superimposed on the satellite signal can be detected.

  The GPS satellite 8 is equipped with an atomic clock, and the satellite signal includes extremely accurate GPS time information measured by the atomic clock. Further, a slight time error of the atomic clock mounted on each GPS satellite 8 is measured by the control segment on the ground, and the satellite signal includes a time correction parameter for correcting the time error. The electronic timepiece 1 receives a satellite signal transmitted from one GPS satellite 8, and uses an accurate time (time information) obtained by using GPS time information and time correction parameters included therein as an internal time. And

  As shown in FIG. 1, the electronic timepiece 1 includes a time display unit including a dial 11 and hands 12. An opening is formed in a part of the dial plate 11 and a display 13 including an LCD display panel is incorporated.

The pointer 12 includes a second hand, a minute hand, an hour hand, and the like, and is driven via a gear by a driving mechanism (step motor) described later.
The display 13 is composed of an LCD display panel or the like.
The electronic timepiece 1 receives satellite signals from a plurality of GPS satellites 8 orbiting the earth over a predetermined orbit to obtain satellite time information, correct internal time information, or obtain positioning information. calculate. Thereby, it is comprised so that various information, such as travel distance at the time of running, speed, pace, etc., can be displayed on the display 13. FIG.

[Schematic configuration of electronic watch]
FIG. 2 is a schematic cross-sectional view of the electronic timepiece 1.
As shown in FIG. 2, the electronic timepiece 1 includes a metal outer case 15, a cover glass 16, and a back cover 17. The exterior case 15 is configured by fitting a bezel 152 made of ceramic or metal to a cylindrical case 151 made of metal. In the case where the bezel 152 is formed of ceramic, the reception performance is improved because the radio wave is not blocked unlike the metal. Further, when the bezel 152 is made of metal, the manufacturing cost can be reduced because it is easier to process than ceramic. Of the two openings of the exterior case 15, the opening on the front side is closed by the cover glass 16 via the bezel 152, and the opening on the back side is closed by the back cover 17 formed of metal. Yes. In addition, a disc-shaped and light-transmitting dial 11 is disposed as a time display portion on the inner peripheral side of the bezel 152 via a ring-shaped dial ring 140 made of plastic.

The pointer 12 includes a pointer (second hand) 121, a pointer (minute hand) 122, and a pointer (hour hand) 123. Further, inside the exterior case 15, a pointer shaft 125 that penetrates the dial plate 11, pointers 121, 122, 123 that circulate around the pointer shaft 125, and a drive mechanism 430 that drives these hands 121, 122, 123. Etc. are provided.
The pointer shaft 125 is provided along a central axis that passes through the center of the outer case 15 in plan view and extends in the front-back direction.
As shown in FIGS. 1 and 2, an opening is formed in a part of the dial plate 11, and a display 13 including an LCD display panel or the like is provided. The dial plate 11, the hands 121, 122, 123 and the display 13 are visible through the cover glass 16.
The position of the display 13 is not limited to the 6 o'clock side with respect to the center of the dial 11, and may be provided at a different position on the dial 11.

  As shown in FIG. 1, on the side surface of the outer case 15, a button 61 is located at the 2 o'clock position, a button 62 is located at the 4 o'clock position, and a crown 63 is located at the 3 o'clock position. Are provided. By operating these buttons 61, 62 and crown 63 corresponding to the operating means of the present invention, an operation signal corresponding to the operation is output. By these button operations, the positioning reception process and the time reception process are switched, and various processes are executed.

  The dial ring 140 has an outer peripheral end that is in contact with the inner peripheral surface of the bezel 152, a flat plate portion that is parallel to the cover glass 16, and an inner peripheral end that is in contact with the dial 11. An inclined portion inclined toward the plate 11 side is provided. The dial ring 140 has a ring shape in a plan view and a mortar shape in a cross-sectional view. A donut-shaped storage space is formed by the flat plate portion of the dial ring 140, the inclined portion, and the inner peripheral surface of the bezel 152, and the ring-shaped antenna body 10 is stored in this storage space. .

  The antenna body 10 is obtained by forming a metal antenna pattern on a ring-shaped dielectric material as a base material by plating, silver paste printing, or the like. The antenna body 10 is disposed on the outer periphery of the dial plate 11, disposed on the inner peripheral surface side of the bezel 152, and further covered with a dial ring 140 formed of plastic and the cover glass 16. Secure reception. As the dielectric, a dielectric material that can be used at high frequencies, such as titanium oxide, can be mixed with the resin and molded, and this makes it possible to further reduce the size of the antenna in combination with the shortening of the wavelength of the dielectric. The antenna body 10 may be a patch antenna using a dielectric as a base material in addition to the ring shape.

  Between the dial plate 11 and the ground plate 191 to which the drive mechanism 430 is attached, a solar panel 90 that performs photovoltaic power generation is provided. The solar panel 90 is a circular flat plate in which a plurality of solar cells (photovoltaic elements) that convert light energy into electric energy (electric power) are connected in series. The solar panel 90 also has a sunlight detection function. The dial 11, the solar panel 90, and the base plate 191 are formed with a hole through which the pointer shaft 125 passes and an opening of the display 13.

  The drive mechanism 430 is attached to the ground plane 191 and covered with a circuit board 192 from the back side. The drive mechanism 430 includes a step motor and a gear train such as a gear, and the step motor drives the hands 121, 122, and 123 by rotating the needle shaft 125 via the wheel train.

The circuit board 192 includes a receiving unit (GPS module) 18 and a control unit 20 as receiving means of the present invention. A circuit holder 193 for covering these circuit components is provided on the back cover 17 side (rear surface side) of the circuit board 192 where the receiving unit 18 and the control unit 20 are provided. Further, the secondary battery 70 such as a lithium ion battery is provided between the ground plane 191 and the back cover 17 and is charged with the electric power generated by the solar panel 90.
The circuit holder 193 is provided with an opening for accommodating the secondary battery 70 in the outer case 15. In addition, a ground plate receiving ring 102 formed in an annular shape is disposed between the circuit board 192 and the antenna body 10.

  The antenna body 10 is fed through a feeding point, and an antenna connection pin 101 is connected to the feeding point. The antenna connection pin 101 is a pin-shaped connector made of metal, is disposed through the ground plane receiving ring 102, and is in contact with the circuit board 192. As a result, the circuit board 192 and the antenna body 10 inside the storage space are connected by the antenna connection pins 101.

[Navigation message]
Here, before the details of the circuit configuration of the electronic timepiece 1 are described, a navigation message that is a satellite signal transmitted from the GPS satellite 8 will be described. The navigation message is modulated into satellite radio waves as 50 bps data.
FIG. 3A to FIG. 3C are diagrams for explaining the configuration of the navigation message.
As shown in FIG. 3 (A), the navigation message is configured as data with a main frame having a total number of 1500 bits as one unit. The main frame is divided into five sub-frames 1 to 5 each having 300 bits. Data of one subframe is transmitted from each GPS satellite 8 in 6 seconds. Therefore, data of one main frame is transmitted from each GPS satellite 8 in 30 seconds.

  Subframe 1 includes satellite correction data such as week number data. The week number data is information representing a week including the current GPS time information. The starting point of the GPS time information is January 6, 1980, 00:00:00 in UTC (Coordinated Universal Time), and the week starting on this day is the week number 0. Week number data is updated on a weekly basis.

  Subframes 2 and 3 include ephemeris parameters (detailed orbit information of each GPS satellite 8). The subframes 4 and 5 include almanac parameters (general orbit information of all GPS satellites 8).

  Further, subframes 1 to 5 include, from the beginning, a TLM (Telemetry) word storing 30-bit TLM (Telemetry word) data and a HOW word storing 30-bit HOW (hand over word) data. It is.

  Therefore, TLM words and HOW words are transmitted from the GPS satellite 8 at intervals of 6 seconds, whereas satellite correction data such as week number data, ephemeris parameters, and almanac parameters are transmitted at intervals of 30 seconds.

  As shown in FIG. 3B, the TLM word includes preamble data, a TLM message, reserved bits, and parity data.

  As shown in FIG. 3C, the HOW word includes GPS time information called TOW (Time Of Week, also referred to as “Z count”). In the Z count data, the elapsed time from 0 o'clock every Sunday is displayed in seconds, and it returns to 0 at 0 o'clock on the next Sunday. That is, the Z count data is information in units of seconds indicated every week from the beginning of the week. This Z count data indicates GPS time information at which the first bit of the next subframe data is transmitted. For example, the Z count data of subframe 1 indicates GPS time information at which the first bit of subframe 2 is transmitted. The HOW word also includes 3-bit data (ID code) indicating the ID of the subframe. That is, ID codes “001”, “010”, “011”, “100”, and “101” are included in the HOW words of subframes 1 to 5 shown in FIG.

  The GPS receiver can acquire GPS time information by acquiring the week number data included in the subframe 1 and the HOW word (Z count data) included in the subframes 1 to 5. However, if the GPS receiver has previously acquired the week number data and is counting the elapsed time since the time when the week number data was acquired internally, the GPS satellite 8 can be obtained without acquiring the week number data. Current over-number data can be obtained. In the cold start state in which the almanac data is not held, even when searching for one GPS satellite 8, the satellite search time needs to be about 10 seconds. Therefore, the reception time is about 15 seconds on average even when the Z count data is acquired after the GPS satellite 8 is captured and the verification time of the reception data is included.

  The TLM word, HOW word (Z count data), satellite correction data, ephemeris parameter, almanac parameter, etc. are examples of satellite information in the present invention.

In the present invention, reception in the time measurement mode means reception of Z count data that is time information. Z count data can also be acquired from one GPS satellite 8. Since the Z count data is included in each subframe, it is transmitted at intervals of 6 seconds.
For this reason, reception in the timekeeping mode means that the number of captured satellites is at least one, the time required to acquire one piece of Z count data is at most 6 seconds, and the information that can be acquired is Z count data ( Time information) and means that the ephemeris parameter or almanac parameter is not received.
One Z-count data can be acquired in 6 seconds, and the reception can be completed in a short time of 12-18 seconds even when acquiring 2-3 Z-count data for verification of the received data. it can.

On the other hand, in the present invention, receiving in the positioning mode means receiving ephemeris parameters that are orbit information of each GPS satellite 8 for three or more satellites. This is because ephemeris parameters need to be acquired from at least three or more GPS satellites 8 for positioning reception. Since the ephemeris parameter is included in subframes 2 and 3, it can be acquired by performing reception for 18 seconds at the shortest (reception from subframes 1 to 3). Therefore, when a plurality of GPS satellites 8 are simultaneously captured and received, in order to obtain positioning data by receiving ephemeris parameters and performing positioning calculation, in a cold start state in which no almanac data is held, the satellite search time is 20 seconds. A degree is necessary. For this reason, the time required for reception in the positioning mode requires about 40 seconds to 1 minute including the satellite search time.
Therefore, the positioning mode reception means that the number of captured satellites is at least 3, the reception time is about 30 seconds to 1 minute, and the information that can be acquired is Z count data (time information) and ephemeris parameters. The almanac parameter means processing that is not received.

In the electronic timepiece 1, reception processing in the timekeeping mode includes automatic reception processing that is automatically received at a predetermined time and manual reception processing that is executed by the user operating the button 61. The positioning mode reception process is a manual reception process executed by the user operating the button 61. Therefore, in the present invention, it is possible to operate by switching between the time measuring mode and the positioning mode.
In the timekeeping mode, GPS week number data is included in subframe 1, so if you want to get even date information, start automatic reception processing at 0 or 30 seconds per minute when subframe 1 is transmitted. If the reception start time is set so that it can be performed, the time information and date information can be received in the shortest required time.
In the time measurement mode, in addition to automatic reception processing (hereinafter referred to as “timed time reception processing”) that is executed at a predetermined time, light automatic that is executed when the solar panel 90 is irradiated with light. There is a time reception process. In addition, since reception in the timekeeping mode should normally be performed once a day, the optical automatic timekeeping reception process ensures reception once a day only when reception fails in the timed timepiece reception process. To do so.

[Circuit configuration of electronic watch]
FIG. 4 is a block diagram showing a main hardware configuration inside the electronic timepiece.
As shown in FIG. 4, the electronic timepiece 1 includes an antenna body 10, a SAW (Surface Acoustic Wave) filter 31, a receiving unit 18, a display control unit 40, and a power supply unit 50. Has been.
The filter 31 may be incorporated in the receiving unit 18.

[Receiver configuration]
The receiving unit 18 includes an RF (Radio Frequency) unit 27 and a baseband unit 30. The filter 31 performs a process of extracting a satellite signal from the signal received by the antenna body 10. That is, the filter 31 is configured as a band-pass filter that passes a 1.5 GHz band signal.

As will be described below, the RF unit 27 and the baseband unit 30 perform processing for acquiring satellite information such as orbit information and GPS time information included in the navigation message from the 1.5 GHz band satellite signal extracted by the filter 31. Do.
The RF unit 27 includes an LNA (Low Noise Amplifier) 47, a mixer 46, a VCO (Voltage Controlled Oscillator) 41, a PLL (Phase Locked Loop) circuit 34, an IF amplifier 48, an IF (Intermediate Frequency) filter 35, an ADC (ADC). A / D converter) 42 and the like.

  The satellite signal extracted by the filter 31 is amplified by the LNA 47. The satellite signal amplified by the LNA 47 is mixed with the clock signal output from the VCO 41 by the mixer 46 and down-converted to an intermediate frequency band signal. The PLL circuit 34 compares the phase of the clock signal obtained by dividing the output clock signal of the VCO 41 with the reference clock signal, and synchronizes the output clock signal of the VCO 41 with the reference clock signal. As a result, the VCO 41 can output a clock signal with a stable frequency accuracy of the reference clock signal. For example, several MHz can be selected as the intermediate frequency.

  The signal mixed by the mixer 46 is amplified by the IF amplifier 48. Here, by the mixing in the mixer 46, a high-frequency signal of several GHz is generated together with the signal in the intermediate frequency band. Therefore, the IF amplifier 48 amplifies a high frequency signal of several GHz together with the signal in the intermediate frequency band. The IF filter 35 passes the signal in the intermediate frequency band and removes the high-frequency signal of several GHz (precisely, attenuates to a predetermined level or less). The intermediate frequency band signal that has passed through the IF filter 35 is converted into a digital signal by an ADC (A / D converter) 42.

The baseband unit 30 includes a CPU (Central Processing Unit) 36, an SRAM (Static Random Access Memory) 37, and a DSP (Digital Signal Processor) 39. The baseband unit 30 is connected to a temperature-compensated crystal oscillation circuit (TCXO: Temperature Compensated Crystal Oscillator) 32, a flash memory 33, and the like.
A crystal oscillation circuit (TCXO) 32 with a temperature compensation circuit generates a reference clock signal having a substantially constant frequency regardless of the temperature.

The flash memory 33 stores time difference information. The time difference information is information in which the time difference of each of a plurality of areas into which geographic information is divided is defined.
When set to the timekeeping mode or the positioning mode, the baseband unit 30 performs a process of demodulating the baseband signal from the digital signal (intermediate frequency band signal) converted by the ADC 42 of the RF unit 27.

Further, when set to the timekeeping mode or the positioning mode, the baseband unit 30 generates a local code having the same pattern as each C / A code in a reception processing step described later, and each baseband unit 30 includes Processing for correlating the C / A code and the local code is performed. Then, the baseband unit 30 adjusts the local code generation timing so that the correlation value for each local code has a peak, and if the correlation value is equal to or greater than the threshold value, it synchronizes with the GPS satellite 8 of that local code (that is, , GPS satellite 8 is captured).
Here, the GPS system employs a CDMA (Code Division Multiple Access) method in which all GPS satellites 8 transmit satellite signals of the same frequency using different C / A codes. Therefore, the GPS satellite 8 can be searched by controlling the search order of the satellites by controlling the generation order of the local codes.

  Furthermore, the baseband unit 30 demodulates the navigation message by mixing the local code having the same pattern as the C / A code of the captured GPS satellite 8 and the baseband signal, and orbit information and GPS time information included in the navigation message. Satellite information such as is acquired and stored in the SRAM 37.

[Configuration of display control unit]
The display control unit 40 includes a control unit (CPU) 20, a pointer 12, and a drive circuit 43 for the display 13.
The control unit 20 includes an RTC (real time clock) 21, a storage unit 22, and a satellite storage unit 23 as hardware.
The RTC 21 corresponding to the time measuring means of the present invention measures the internal time information using the reference signal output from the crystal resonator.
The storage unit 22 stores time data and positioning data output from the receiving unit 18. The storage unit 22 also stores time difference data corresponding to the positioning information, so that the local time of the current location can be calculated from the internal time information and time difference data measured by the RTC 21.

The satellite storage unit 23 corresponds to the satellite storage means of the present invention and has a function of storing information related to the GPS satellite 8.
FIG. 5 is a diagram showing information related to the GPS satellite 8 stored in the satellite storage unit 23 of the electronic timepiece 1.
As shown in FIG. 5, the satellite storage unit 23 as the satellite storage unit of the present invention includes a satellite number of the GPS satellite 8 captured by the reception unit 18 when a time measurement reception process described later is executed, and In addition to the capture time when the GPS satellite 8 corresponding to the reception execution time of the present invention is captured, the Doppler frequency corresponding to the satellite information of the present invention is stored. These pieces of information are acquired by the receiving unit 18 and updated by overwriting the previously stored data every time the time measurement receiving process is executed. In the present embodiment, since the receiving unit 18 includes a maximum of four channels (receiving units), for example, a maximum of four GPS satellites 8, the satellite numbers of the four GPS satellites 8, and the four GPS satellites 8 Acquisition time and Doppler frequency are stored. In addition to these pieces of information, a received signal level (SNR: Signal to Noise Ratio) may be stored. The satellite storage unit 23 may be a RAM (Random Access Memory) configured in the CPU or a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory).

As shown in FIG. 6, the control unit 20 includes a time measurement processing unit 201, a positioning processing unit 202, a display control unit 203, a voltage detection control unit 204, a time information correction unit 205, a reception control unit 206, a mode determination unit 207, It functions as the satellite search mode determination means 208 and the satellite search order setting means 209.
The time measurement processing means 201 searches for at least one GPS satellite 8 and executes reception processing of time information (time data) from the captured GPS satellite 8 (hereinafter referred to as time measurement reception processing).
The positioning processing unit 202 searches for three or more GPS satellites 8 when a positioning operation (an operation of pressing the button 61 for the first set time (6 seconds or more)) is performed by the user, and the captured GPS satellites 8 are captured. Using the satellite orbit information (ephemeris) of the satellite signal transmitted from, the current location positioning calculation is executed, and processing for acquiring positioning data and time information (hereinafter referred to as positioning reception processing) is performed.
The display control unit 203 performs processing for controlling display of the pointer 12 and the display 13 via the drive circuit 43.
The voltage detection control means 204 controls the operation of the voltage detection circuit 54 described later to perform voltage detection processing for the secondary battery 70.
The time information correcting unit 205 performs a process of correcting the internal time based on the acquired time information.

In addition to controlling the receiving unit 18, the reception control unit 206 has a function of selecting a search mode for the GPS satellite 8 by the receiving unit 18 and causing the receiving unit 18 to capture the GPS satellite 8 and receive the satellite signal.
Here, a mode for searching for the GPS satellite 8 by the receiving unit 18 will be described. First, there are two types of modes for searching for the GPS satellite 8: a fixed search mode and a priority search mode. In the fixed search mode, the GPS satellites 8 are searched in order from a predetermined order, for example, from the satellite number (SV1). On the other hand, in the priority search mode, the GPS satellite 8 captured in the previous time measurement reception process is preferentially searched based on the satellite number stored in the satellite storage unit 23, and then the priority search is performed. GPS satellites 8 other than the searched GPS satellites 8 are searched in the order of the satellite numbers.
That is, the reception control unit 206 selects either the fixed search mode or the priority search mode, and causes the reception unit 18 to execute the reception process of the GPS satellite 8.

  The mode determination unit 207 has a function of determining whether the time reception process in the time measurement reception mode is being executed or the position reception process in the position reception mode being executed when the reception process is executed. .

The satellite search mode determination unit 208 corresponding to the determination unit of the present invention will be described in detail later, but a forced timed reception process (for example, a manual timed reception process or an optical automatic timed reception) other than the timed timed reception process. When the process is executed, the elapsed time from the reception execution time (capture time of the GPS satellite 8) stored in the satellite storage unit 23 when the previous time measurement reception process is executed is predetermined from the 24-hour period. (For example, within a range of 24 hours × n ± 2 hours). Accordingly, when it is determined that the capture time of the GPS satellite 8 stored in the satellite storage unit 23 when the previous time measurement reception process is executed is within the range of 24 hours × n ± 2 hours, reception control is performed. Means 206 selects a priority search mode.
In the present embodiment, when the timed reception process is being executed, the timed reception process in the priority search mode is always executed, so in the case of the timed time reception process, The determination process by the satellite search mode determination unit 208 is not executed.

The satellite search order setting unit 209 has a function of setting the search order of the GPS satellites 8 in the priority search mode. For example, when the number of GPS satellites 8 that can be captured in the previous time measurement reception process is four, the search order of the four GPS satellites 8 is determined. This search order is determined, for example, in descending order of the Doppler frequency of the GPS satellites 8. The search order is not limited to the Doppler frequency, and may be, for example, the order of satellite numbers with high SNR.
Since the search order of the GPS satellites 8 in the fixed search mode is stored in the storage unit 22 in advance, when the reception process in the fixed search mode is executed, the setting process by the satellite search order setting unit 209 is executed. Not.

  On the other hand, the CPU 36 is also provided in the baseband unit 30, and this CPU 36 functions when an instruction to receive time information or a positioning process is instructed from the control unit 20. Specifically, the satellite number of the received satellite signal, frequency offset data corresponding to the Doppler frequency, and pseudorange data corresponding to the code phase for C / A code correlation are acquired.

[Configuration of power supply unit]
As shown in FIG. 4, the power supply unit 50 includes a solar panel 90, a charge control circuit 51, a secondary battery 70, a first regulator 52, a second regulator 53, and a voltage detection circuit 54.

The secondary battery 70 supplies driving power to the display control unit 40 via the first regulator 52 and supplies driving power to the receiving unit 18 via the second regulator 53.
The solar panel 90 supplies power to the secondary battery 70 through the charge control circuit 51 to charge the secondary battery 70.
When the solar panel 90 is irradiated with light (for example, sunlight) and power generation by the solar panel 90 is started, the charging control circuit 51 outputs a light detection result to the control unit 20.
Further, the voltage detection circuit 54 monitors the voltage of the secondary battery 70 and outputs it to the control unit 20. Therefore, the control unit 20 can control the reception process by grasping the light detection result or the voltage of the secondary battery 70.

[GPS satellite orbit]
Next, the orbit of the GPS satellite 8 which is a specific example of the position information satellite in the present embodiment will be described. FIG. 7 shows a time zone in which all 31 GPS satellites 8 (G01 to G31) appear in the sky (example of a city on January 1, 2009). In FIG. 7, a thick solid line portion indicates a time zone in which each GPS satellite 8 can be received when a GPS satellite 8 with an elevation angle of 10 degrees or more is captured, that is, when the elevation mask is set to 10 degrees. Show.
As can be seen from FIG. 7, when the elevation angle mask is set to 10 degrees, about 4 to 8 GPS satellites 8 can be captured at all times, and the time during which each GPS satellite 8 can be captured is approximately 4 hours. . Since the GPS satellites 8 pass through the same orbit approximately every 24 hours, there is a high possibility that the same GPS satellites 8 (positional information satellites) can be captured within a range of 24 hours × n ± 2 hours.

On the other hand, FIG. 8 is a diagram showing a change in the elevation angle of the GPS satellite 8 over time. As an example, the change in the elevation angle of each GPS satellite 8 from 0:00 to 9:00 in FIG. 7 is shown.
Here, when the elevation angle is high, since the distance between the GPS satellite 8 and the electronic timepiece 1 is close, the pseudorange data becomes small. Also, since the signal is strong, the SNR increases and the relative speed decreases, so the frequency shift decreases. Further, when the elevation angle is low and the satellite rises from this point, the distance to the GPS satellite 8 is large, so the pseudorange data becomes large, the SNR becomes small, and the Doppler frequency becomes high. On the other hand, when the GPS satellite 8 is going to sink, the pseudorange data is large, the SNR is small, and the Doppler frequency is low.
Therefore, if the Doppler frequency is stored as satellite information in the satellite storage unit 23 and these data are read during the time measurement process, the satellite orbit can be easily predicted without acquiring the almanac. Further, since the frequency for searching for the GPS satellite 8 can be set in advance based on the Doppler frequency, the search time for the GPS satellite 8 can be shortened. In the present embodiment, only the Doppler frequency is stored in the satellite storage unit 23. However, in addition to the Doppler frequency, SNR and pseudorange data may be stored.

[Receive processing]
Hereinafter, a procedure of reception processing in the electronic timepiece 1 of the present embodiment will be described.
First, the timed reception process by the timekeeping processing unit 201 will be described with reference to the flowchart of FIG.

[Timed reception processing]
The scheduled time reception process is a process for starting the reception process at the same time (timed) every day. At this fixed time, the user sets the time at which the user is outdoors, such as when commuting with a high reception success rate. The time measurement processing unit 201 of the electronic timepiece 1 determines whether or not the internal clock timed by the RTC 21 has reached a preset reception time (reception timing) (S11). Thereby, if it is not the reception time (NO in S11), the time measurement processing unit 201 repeatedly executes the determination process of S11.
On the other hand, when the reception time comes in S11 (YES in S11), the time measurement processing unit 201 outputs a control signal instructing the baseband unit 30 to start reception and starts reception processing in the time measurement mode. (S12).

Here, in the timed reception process, since the priority search mode is always selected, the reception control means 206 selects the search mode of the GPS satellite 8 as the priority search mode, and the satellite search order setting means. The search order of the GPS satellites 8 is set by 209 (S13). When the reception process is started, the receiving unit 18 performs a satellite search process for the GPS satellite 8 (S14). The satellite search process of the GPS satellite 8 is executed, for example, for 30 seconds to 1 minute, and a plurality of satellite signals are received by continuing the satellite search process.
Thereafter, the time measurement processing unit 201 determines whether or not at least one GPS satellite 8 has been captured (S15). Specifically, the time measurement processing unit 201 determines whether or not it has received a capture signal that captures at least one GPS satellite 8 transmitted from the baseband unit 30. Thus, when it is determined that at least one GPS satellite 8 has not been captured (the capture signal transmitted from the baseband unit 30 has not been received) (NO in S15), the elapsed time from the start of reception in S12 It is determined whether or not a predetermined timeout time (for example, 60 seconds) has been reached (S16).

When the time-out processing unit 201 times out in S16 and times out (YES in S16), the time measurement processing unit 201 ends the reception process (S20).
On the other hand, if time-out processing means 201 has not timed out in S16 (NO in S16), the search for GPS satellite 8 in S14 is continued, so whether GPS satellite 8 could be captured again in S15. Determine whether or not.

  When the time measurement processing unit 201 determines that the GPS satellite 8 has been captured (YES in S15), the satellite search order setting unit 209 updates the received information about each GPS satellite 8 (hereinafter referred to as satellite data). And stored in the satellite storage unit 23 (S17). Specifically, the satellite search order setting unit 209 selects the satellite having the best condition (SNR is large and pseudorange data is small) with reference to the signal level (SNR) of each satellite data, and the acquired satellite Among the above data, data up to four satellites in the descending order of SNR are stored in the satellite storage unit 23 (S17). At this time, the satellite search order setting unit 209 stores the captured satellite data of the GPS satellite 8 in the satellite storage unit 23 regardless of whether or not the Z count has been acquired.

  Then, the time measurement processing unit 201 continues to receive the satellite signal under the best condition and determines whether time information (Z count) has been acquired (S18). Thereby, when it is determined that the time information cannot be acquired (NO in S18), whether or not the time information has been acquired until a predetermined time (for example, 60 seconds) elapses (NO in S19). Make a decision. If it is determined in S19 that a timeout has occurred (YES in S19), the time measurement processing unit 201 ends the reception process (S20).

On the other hand, when the time information has been acquired in S18 (YES in S18), the time measurement processing unit 201 confirms the consistency of the acquired time information (Z count) (S21). Specifically, the time measurement processing unit 201 compares the Z count with the time data of the RTC 21 of the control unit 20 at the time when the first Z count is acquired, and determines whether or not the difference is within a predetermined value. It is confirmed whether or not matching is achieved (S21). In S21, when the difference in the compared time is too large (for example, when there is a difference of 5 seconds or more), it is determined that the matching is not achieved.
And when it determines with NO by S21, the time measurement process means 201 repeats the process of S19, S18, S21. In the GPS satellite signal, the Z count can be received at intervals of 6 seconds. Therefore, if the timeout time of S19 is 60 seconds, it is possible to determine whether the Z count is received and matched until the timeout occurs. Therefore, when the acquired Z count is not consistent with the internal time, the Z count of the subframe after the next 6 seconds is acquired.
And when the time measurement processing means 201 acquires a plurality of Z counts, if the plurality of Z counts are consistent with each other, that is, if the data is at intervals of 6 seconds, It is determined that the count (time data) is consistent.

When the time-out occurs in S19, the time measurement processing unit 201 ends the reception (S20).
On the other hand, when it can be confirmed that there is a match in S21 (YES in S21), the time measurement processing unit 201 ends the reception (S22), and the time information correction unit 205 of the control unit 20 adds the acquired time data. Based on this, the time information is corrected (S23). When the time is corrected, the display control unit 203 corrects the display of the pointer 12 via the drive circuit 43. As described above, the scheduled time reception processing is completed.

[Forced time reception processing]
FIG. 10 is a flowchart showing the procedure of forced time measurement reception processing. In FIG. 10, the same reference numerals are given to the same procedures as those in the timed reception process.
The forced time measurement reception process is a manual time measurement reception process executed when the user operates the button 61 for a second set time (for example, 3 seconds or more and less than 6 seconds) and when the solar panel 90 is irradiated with light. This refers to the automatic optical time measurement reception process executed in In the following description, the same procedure as the timed reception process is described in detail while omitting the description.

First, the time measurement processing unit 201 of the electronic timepiece 1 determines whether or not a predetermined input has been made (S31). Specifically, the time measurement processing unit 201 determines whether or not the user has operated the second set time of the button 61 or when the solar panel 90 is irradiated with light, that is, the light control circuit 51 emits light. It is determined whether the detection result or information indicating that the voltage of the secondary battery 70 has been increased is transmitted to the control unit 20 by the voltage detection circuit 54. Since the time measurement reception process is normally performed once a day, the optical automatic time measurement reception process is executed only when reception of time information fails in the regular time measurement reception process. Thereby, if there is no predetermined input (NO in S31), the time measurement processing unit 201 repeatedly executes the determination process of S31.
On the other hand, when it is determined in S31 that there is a predetermined input (YES in S31), the time measurement processing unit 201 outputs a control signal instructing the baseband unit 30 to start reception to receive in the time measurement mode. The process is started (S32).

The satellite search mode determination unit 208 then sets the elapsed time from the reception execution time (the capture time of the GPS satellite 8) stored when the previous reception process is executed within the range of 24 hours × n ± 2 hours. It is determined whether or not there is (S33). Accordingly, when it is determined that the capture time of the GPS satellite 8 stored when the previous reception process is executed is not within the range of 24 hours × n ± 2 hours (NO in S33), the reception control means 206 Then, the fixed search mode (normal search mode) is selected, and the search order (for example, satellite number order) of the GPS satellites 8 stored in advance in the storage unit 22 is set (S34).
On the other hand, if it is determined that the elapsed time from the capture time of the GPS satellite 8 stored when the previous reception process is executed is within the range of 24 hours × n ± 2 hours (YES in S33), the reception The control means 206 switches the search mode of the GPS satellites 8 to the priority search mode, and all the GPS satellites 8 are preferentially searched for the GPS satellites 8 stored in the satellite storage unit 23 by the satellite search order setting means 209. The search order is set (S35). When the reception process is started, the reception unit 18 executes the satellite search process for the GPS satellite 8 in the order set in S34 and S35 (S14). And the control part 20 performs the process similar to said process S14-S23, and complete | finishes a forced time reception process.

[Positioning reception processing]
The positioning processing means 202 searches for three or more GPS satellites 8 in the fixed search mode when the user presses the button 61 for the first set time (6 seconds or more), and the satellites transmitted from the captured GPS satellites 8 The positioning calculation of the present location is executed using the satellite orbit information (ephemeris) of the signal, and processing for acquiring positioning data and time information is executed. As described above, the positioning reception process by the positioning processing unit 202 is executed, so that the user can acquire the position information.
In the present embodiment, in the positioning reception process, the GPS satellite 8 is always searched in the fixed search mode. Further, when the positioning reception process is executed, the satellite number, the capture time, and the Doppler frequency of the GPS satellite 8 captured by the positioning reception process are not stored in the satellite storage unit 23.

[Effects of First Embodiment]
The electronic timepiece 1 according to the first embodiment of the present invention described above has the following effects.
According to the present embodiment, the time measurement processing unit 201 executes reception processing in the priority search mode at the time of scheduled reception, so that the GPS satellite of the satellite number stored in the satellite storage unit 23 at a preset reception time. Since the search is prioritized, it is highly possible that the search for the GPS satellite 8 can be completed only by searching for the GPS satellite 8 that is the priority search target. Thereby, it is possible to prevent a search for useless GPS satellites 8. Therefore, the average search time of the GPS satellite 8, that is, the satellite signal reception time can be shortened, and the power consumption can be reduced. In particular, since the electronic timepiece 1 searches for the GPS satellite 8 in a cold start state in which the almanac data is not always received and held, the search time of the GPS satellite 8 is longer than that of a general GPS device that receives and holds the almanac data. However, the present embodiment is particularly effective because it is highly possible that the search process can be completed only by searching for the GPS satellites 8 to be preferentially searched, that is, the number of searches for the GPS satellites 8 can be reduced.

In the forced time reception process, if the reception process in the priority search mode is always executed as in the timed time reception process, there is a possibility that a satellite that cannot be received may be searched. It may be better not to search for satellites by mode. On the other hand, in this embodiment, it is determined whether or not the elapsed time from the capture time of the GPS satellite 8 of the satellite number stored in the satellite storage unit 23 is within a range of 24 hours × n ± 2 hours. Since the reception process in the priority search mode is executed when the elapsed time is within the range of 24 hours × n ± 2 hours, the reception process can be executed when the reception process in the priority search mode is valid. That is, when the forced time reception processing (manual time reception processing and optical automatic time reception processing) is executed, the elapsed time from the capture time of the GPS satellite 8 stored in the satellite storage unit 23 is 24 hours × Since reception processing in the priority search mode is executed when it is within the range of n ± 2 hours, it is only necessary to search for a GPS satellite 8 (a GPS satellite 8 in which the satellite number is stored) as a priority search target. There is a high probability that 8 searches can be completed. On the other hand, when execution of forced time reception processing is instructed, if the elapsed time from the reception execution time stored in the satellite storage unit 23 is not within the range of 24 hours × n ± 2 hours, a fixed search is performed. The reception process according to the mode is executed. That is, when the elapsed time from the reception execution time stored in the satellite storage unit 23 is not within the range of 24 hours × n ± 2 hours, the GPS satellite 8 having the satellite number stored in the satellite storage unit 23 is captured. It is unlikely to be possible. For this reason, when the elapsed time is not within the range, the search for the GPS satellite 8 in the fixed search mode is executed without executing the search for the GPS satellite 8 in the priority search mode. Therefore, even in the case of forced measurement reception processing, it is possible to prevent a search for useless GPS satellites 8, so that an average search time for GPS satellites 8 can be shortened and power consumption can be reduced.
Further, since the satellite storage unit 23 stores the satellite number and the reception execution time of the received GPS satellite 8, the memory capacity can be reduced as compared with the case where the reception history of the position information satellite every 8 minutes is created. The electronic watch 1 can be reduced in size and manufacturing cost.

In the present embodiment, when the positioning reception process is executed, the search in the fixed search mode is always executed. When the positioning reception process is executed, there is a possibility that it is performed in a place (for example, a different country) different from the place where the user executed the positioning reception process last time, and the elapsed time from the time stored in the satellite storage unit 23 Even if the position information satellite is searched for in the priority search mode according to time, the possibility of searching for the same position information satellite is low. That is, in the present embodiment, when the positioning reception process is executed, the satellite signal reception process in the priority search mode is not performed, so that it is possible to prevent a search for useless GPS satellites 8.
Therefore, even when any of the time measurement process and the positioning process is executed, the search for the useless GPS satellite 8 is prevented, so that the average search time for the GPS satellite 8 can be shortened and the power consumption can be reduced. .

  In this embodiment, since the Doppler frequency is stored as the satellite information in the satellite storage unit 23, the frequency for searching for the GPS satellite 8 can be set in advance based on the Doppler frequency. Thereby, when the GPS satellite 8 is searched in the priority search mode, the frequency for searching for the GPS satellite 8 can be set instantaneously, so that the GPS satellite 8 can be reliably captured in a short time. Therefore, the average search time of the GPS satellite 8 can be shortened, and the power consumption can be reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
In the electronic timepiece 1A according to the second embodiment of the present invention, the satellite search mode determination unit 208 includes a first determination unit 208A and a second determination unit 208B, and the satellite storage unit 23 corresponding to the satellite storage unit of the present invention is provided. The point provided with a 1st storage area and a 2nd storage area, and the process sequence at the time of performing a timetable reception process differ.
Therefore, the different points will be described in detail below based on FIG. 11 and FIG.

FIG. 11 is a diagram illustrating a configuration of a control unit of an electronic timepiece according to the second embodiment of the present invention.
In the present embodiment, the satellite search mode determination unit 208 of the control unit 20 includes a first determination unit 208A and a second determination unit 208B as shown in FIG.
Although not shown, the satellite storage unit 23 provided in the control unit 20 includes a first storage area and a second storage area.
In the first storage area, the satellite number of the GPS satellite 8 captured by the previous scheduled time reception process, the scheduled reception execution time when the previous scheduled time reception process was executed (the capture time of the GPS satellite 8) The Doppler frequency as satellite information and the received signal level (SNR) are stored.
In the second storage area, the satellite number of the GPS satellite 8 captured by the previous forced time reception process (manual time reception process and optical automatic time reception process) and the previous forced time reception process were executed. The forced reception execution time (capture time of the GPS satellite 8), the Doppler frequency as the satellite information, and the received signal level (SNR) are stored.

  The first determination unit 208A captures the GPS satellite 8 stored in the first storage area of the satellite storage unit 23 when the previous timed time receiving process is executed when the timed time receiving process is executed. A function is provided for determining whether the elapsed time from the time is within a range of 24 hours × n ± 2 hours. The second determination unit 208B captures the GPS satellite 8 stored in the second storage area of the satellite storage unit 23 when the previous forced time reception process is executed when the forced time reception process is executed. A function is provided for determining whether the elapsed time from the time is within a range of 24 hours × n ± 2 hours. That is, the second determination unit 208B has the same function as the satellite search mode determination unit 208 of the first embodiment.

  FIG. 12 is a flowchart showing the procedure of the timed reception process of the electronic timepiece 1A. In FIG. 12, the same steps as those in the timed reception process in FIG. 9 are given the same numbers.

The time measurement processing unit 201 of the electronic timepiece 1A determines whether or not the internal clock timed by the RTC 21 has reached a preset reception time (reception timing) (S11). Thereby, if it is not the reception time (NO in S11), the time measurement processing unit 201 repeatedly executes the determination process of S11.
On the other hand, when the reception time comes in S11 (YES in S11), the time measurement processing unit 201 outputs a control signal instructing the baseband unit 30 to start reception and starts reception processing in the time measurement mode. (S12).

Then, the first determination unit 208A of the satellite search mode determination unit 208 has an elapsed time of 24 from the scheduled reception execution time (the capture time of the GPS satellite 8) stored when the previous scheduled time reception process is executed. It is determined whether it is within the range of time × n ± 2 hours (S41). Accordingly, if it is determined that the capture time of the GPS satellite 8 stored when the previous timed reception process is executed is not within the range of 24 hours × n ± 2 hours (NO in S41), reception control is performed. The means 206 selects the fixed search mode (normal search mode), and sets the search order (for example, satellite number order) of the GPS satellites 8 stored in advance in the storage unit 22 (S42).
On the other hand, when it is determined that the elapsed time from the capture time of the GPS satellite 8 stored when the previous timed reception process is executed is within the range of 24 hours × n ± 2 hours (YES in S41). ), The reception control means 206 switches the search mode of the GPS satellites 8 to the priority search mode, and all the GPS satellites are preferentially searched for the GPS satellites 8 stored in the satellite storage unit 23 by the satellite search order setting means 209. The search order of the satellite 8 is set (S43). Then, when the timed reception process is started, the receiving unit 18 executes the satellite search process for the GPS satellite 8 in the order set in S42 and S43 (S14). And the control part 20 performs the process similar to said process S14-S23, and complete | finishes a regular time reception process.

[Effects of Second Embodiment]
According to the electronic timepiece 1A in the second embodiment of the present invention described above, in addition to the same effects as the electronic timepiece 1 in the first embodiment, there are the following effects.

  For example, in the first embodiment, the GPS satellite 8 is always searched for in the priority search mode when the timed reception process is executed. For this reason, after the scheduled time reception process is executed, the forced time reception process is executed. After that, when the scheduled time reception process is executed, the forced time reception process is performed during the scheduled time reception process. When the process is executed, the GPS satellite 8 having the satellite number stored in the satellite storage unit 23 is preferentially searched. For this reason, when the priority search mode is always selected, there is a possibility that the GPS satellite 8 cannot be captured even if the GPS satellite 8 targeted for priority search is searched. On the other hand, in this embodiment, unlike the first embodiment, in the timed reception process, according to the elapsed time from the scheduled reception execution time stored together with the satellite number in the first storage area of the satellite storage unit 23. The GPS satellite 8 is searched by selecting either the priority search mode or the fixed search mode as the mode for searching for the GPS satellite 8. Thereby, since the mode for searching for the GPS satellite 8 is selected according to the elapsed time from the previous scheduled reception execution time, there is a high possibility that the GPS satellite 8 can be quickly captured. For this reason, since the acquisition time of the average GPS satellite 8 can be shortened, the search time of the GPS satellite 8, that is, the reception time of the satellite signal can be shortened, and the power consumption can be reduced.

In the present embodiment, the satellite storage unit 23 includes a first storage area in which the satellite number of the GPS satellite 8 captured by the regular time reception process, the capture time of the GPS satellite 8, and the like are stored, and the forced time reception process. A second storage area in which the satellite number of the GPS satellite 8 captured by (manual timing reception processing and optical automatic timing reception processing), the capture time of the GPS satellite 8, and the like are stored. Information regarding GPS satellites can be stored for each time measurement reception process. Further, when the first determination unit 208A of the satellite search mode determination unit 208 executes the timed reception process, the elapsed time from the GPS satellite capture time (timed reception execution time) stored in the first storage area. It is determined whether it is within a range of 24 hours × n ± 2 hours. As a result, when the timed reception process is executed, the reception process in the priority search mode can be executed with a very high probability, so that a useless search for the GPS satellite 8 can be prevented.
On the other hand, the elapsed time from the capture time (forced reception execution time) of the GPS satellite 8 stored in the second storage area when the second determination means 208B of the satellite search mode determination means 208 executes the forced time reception process. It is determined whether it is within a range of 24 hours × n ± 2 hours. Thus, for example, if the forced timed reception process is an automatic timed reception process, there is a high possibility that the solar panel 90 is irradiated with light at a fixed time every day, so the reception process in the priority search mode is high. Can be executed with probability. For this reason, useless search for the GPS satellite 8 can be prevented in both the regular time reception process and the forced time reception process. Therefore, the average search time of the GPS satellite 8 can be shortened, and the power consumption can be reduced.

  In the present embodiment, since the reception signal level (SNR) is stored as satellite information in the first storage area and the second storage area of the satellite storage unit 23, for example, the first storage area and the second storage area of the satellite storage unit 23 are stored. When there are a plurality of satellite numbers stored in the storage area, the priority order for searching the GPS satellites 8 in order from the GPS satellite 8 with the highest probability that the satellite search order setting unit 209 can capture is set based on the SNR. Thereby, when searching for the GPS satellites 8 in the priority search mode, the GPS satellites 8 can be searched in order from the GPS satellites 8 with the highest priority, so that the GPS satellites can be reliably captured in a short time. Therefore, the average search time of the GPS satellite 8 can be shortened, and the power consumption can be reduced.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  In each of the above embodiments, the satellite storage unit 23 stores the satellite number and the capture time of the GPS satellite 8 captured by the previous time measurement reception process. The captured satellite number and acquisition time may be stored. That is, in the first embodiment, the satellite storage unit 23 stores not only the satellite number and the acquisition time of the GPS satellite 8 captured by the previous time measurement reception process, but also the past several times (for example, three times). A plurality of satellite numbers and acquisition times of the GPS satellites 8 acquired in the time reception process may be stored. In the second embodiment, the first storage area of the satellite storage unit 23 stores a plurality of satellite numbers and capture times of the GPS satellites 8 captured by the past several timed reception processes, and the satellite storage unit The second storage area 23 may store a plurality of satellite numbers and acquisition times of the GPS satellites 8 acquired by the past several forced time reception processes. In these cases, the satellite search mode determination means 208 is 24 hours × n ± 2 hours from any of the plurality of acquisition times stored in the satellite storage unit 23 (first storage area and second storage area). If it is within the range, reception processing in the priority search mode can be executed. According to this, the possibility that the timed reception process in the priority search mode can be executed is increased, and the possibility that the search time for the GPS satellite 8 can be further reduced is further increased.

  In the above modification, the GPS satellite 8 captured by the satellite search mode determination means 208 in a plurality of times (for example, the previous time and the previous time) of the time measurement reception processes of the past several times (for example, three times). If it is determined that the elapsed time from the capture time is within the range of 24 hours × n ± 2 hours, for example, the elapsed time from the previous capture time is within the range of 24 hours × n + 1 hour, When the elapsed time from the previous acquisition time is within the range of 24 hours × n−30 minutes, the search may be performed in the priority search mode in order from the GPS satellite 8 corresponding to the previous acquisition time with less error.

In the second embodiment, when the forced time reception process is executed, the second determination unit 208B stores the second time in the second storage area of the satellite storage unit 23 when the previous forced time reception process is executed. The function of determining whether or not the elapsed time from the captured time (forced reception execution time) of the GPS satellite 8 is within the range of 24 hours × n ± 2 hours is provided. . For example, in addition to the above function, when the forced timed reception process is executed, the GPS satellite 8 stored in the first storage area of the satellite storage unit 23 when the previous timed time reception process is executed is captured. You may make it provide the function to determine whether the elapsed time from time (scheduled reception execution time) is in the range of 24 hours × n ± 2 hours.
According to this, when the forced time reception process is executed, whether the elapsed time from both the forced reception execution time and the scheduled reception execution reception time is within the range of 24 hours × n ± 2 hours. Determine whether. That is, if any of the elapsed time from the scheduled reception time and the elapsed time from the forced reception time is within the range of 24 hours × n ± 2 hours, the storage area to be determined (the first storage area and the second storage area) The time measurement reception process in the priority search mode is executed using the satellite number stored in any one of the above. Therefore, the priority search is performed with a higher probability than when only the elapsed time from the forced reception execution time stored in the second storage area of the satellite storage unit 23 is determined when the forced measurement reception process is executed. Can perform forced measurement reception processing by mode. Therefore, the search time for the GPS satellite 8 can be further shortened, and the power consumption can be reduced.

  Further, in the above modified example, the first determination unit 208A, like the second determination unit 208B, has elapsed from both the forced reception execution time and the scheduled reception execution reception time when the scheduled reception process is executed. It may be determined whether or not the time is within a range of 24 hours × n ± 2 hours. According to this, compared with the case where only the elapsed time from the scheduled reception execution time stored in the first storage area of the satellite storage unit 23 is determined when the scheduled time reception process is executed, the probability is higher. Timed reception processing in the priority search mode can be executed. Therefore, the search time for the GPS satellite 8 can be further shortened, and the power consumption can be reduced.

  Moreover, although the time which captured the GPS satellite 8 was illustrated as reception execution time (regular reception execution time and forced reception execution time), it is not restricted to this. For example, it may be a time when reception processing is started or a time when a satellite signal transmitted from the GPS satellite 8 is received.

  In each of the embodiments described above, at least one of the Doppler frequency and the received signal level (SNR) is stored in the satellite storage unit 23 as satellite information, but the present invention is not limited to this. For example, it is not necessary to store any satellite information. According to this, the capacity of the satellite storage unit 23 (memory) can be further reduced, and the electronic timepiece 1 and 1A can be reduced in size and the manufacturing cost can be reduced.

In the second embodiment, the satellite storage unit 23 includes the first storage area and the second storage area. However, the present invention is not limited to this. For example, a GPS satellite stored in the satellite storage unit 23 every time, regardless of whether the timed time reception process or the forced timed reception process is executed without providing the first storage area and the second storage area The satellite number, the acquisition time, and the satellite information (eg, Doppler frequency or received signal level (SNR)) of 8 may be updated (overwritten). According to this, since the capacity | capacitance of the satellite memory | storage part 23 (memory) can be made further smaller, size reduction of electronic timepiece 1A and manufacturing cost can be reduced.
In such a case, the satellite search mode determination unit 208 does not need to include the first determination unit 208A and the second determination unit 208B, and the single time search mode determination unit 208 performs the timed reception process and the forced search. Regardless of which time measurement reception process is executed, the GPS satellite 8 stored in the satellite storage unit 23 when the previous time measurement reception process (either the regular time reception process or the forced time reception process) is executed. What is necessary is just to determine whether the elapsed time from the capture time is within the range of 24 hours × n ± 2 hours. That is, the reception control means 206 may switch between the priority search mode and the fixed search mode according to the elapsed time.

  In each of the above embodiments, the satellite search mode determination unit 208 determines whether or not the elapsed time from the reception execution time is within the range of 24 hours × n ± 2 hours, but is not limited thereto. . For example, it may be within a range of 24 hours × n ± 1 hour, or within a range of 24 hours × n ± 30 minutes.

  In each of the above embodiments, the fixed search mode is always selected when the positioning reception process is executed, but the present invention is not limited to this. For example, when executing the positioning reception process, the priority search mode may be executed according to the elapsed time from the reception execution time stored in the satellite storage unit 23. For example, when the user is running at a fixed time every day, if the GPS satellite 8 is searched in the priority search mode, the location information can be acquired earlier, so that the convenience of the user can be improved. .

  In each of the above embodiments, a rechargeable secondary battery such as a lithium ion battery is used as the secondary battery 70, but a primary battery such as a lithium battery may be used. In addition, the charging method when the secondary battery is provided is not limited to charging by the power generated by the solar panel 90 as in the present embodiment. For example, instead of the solar panel 90, a generator using a rotating weight may be provided in the electronic timepiece 1 or 1A, or a charging coil or the like is provided and charged by an electromagnetic induction method from an external charger. Alternatively, charging may be performed by connecting to a cradle or the like.

  Although the GPS satellite 8 has been described as an example of the position information satellite, the present invention is not limited to this. For example, as the position information satellite, a satellite used in other global public navigation satellite systems (GNSS) such as Galileo (EU), GLONASS (Russia), and Beidou (China) can be applied. A satellite that can be searched only in a specific area, such as a quasi-zenith satellite (QZSS), can also be applied. In the GNSS other than the GPS satellite 8 where the satellite arrangement is not a 24-hour period, the satellite search mode determination unit 208 may set an elapsed time from the reception execution time according to the period of each satellite arrangement.

  DESCRIPTION OF SYMBOLS 1,1A ... Electronic timepiece, 8 ... GPS satellite (position information satellite), 18 ... Reception part (reception means), 20 ... Control part, 201 ... Time measurement processing means, 202 ... Positioning processing means, 206 ... Reception control means, 208 ... Satellite search mode determination means (determination means), 208A ... first determination means, 208B ... second determination means, 23 ... satellite storage unit (satellite storage means, first storage area and second storage area), 61 ... button (Operation means).

Claims (8)

Receiving means for capturing a position information satellite and receiving a satellite signal transmitted from the captured position information satellite;
Receiving control means for controlling the receiving means to perform receiving processing;
A time measuring means for measuring time;
Satellite storage means for storing the satellite number of the position information satellite captured by the receiving means and the reception execution time at which the reception processing was executed, and
The reception control means includes a fixed search mode for causing the reception means to search for the position information satellites in a predetermined order;
A priority search mode for causing the receiving means to preferentially search for a position information satellite of the satellite number stored in the satellite storage means,
When performing the reception process by the receiving means, according to the elapsed time from the past reception execution time stored in the satellite storage means, select one of the fixed search mode and the priority search mode, A timepiece that searches for the position information satellite. The timepiece according to claim 1,
The reception control means executes the reception process in the priority search mode at the time of a scheduled reception process that is activated when the time measured by the time measuring means reaches a preset reception time. Watch that. The timepiece according to claim 1 or 2,
Operating means for executing the receiving process by the receiving means;
Determination means for determining whether or not an elapsed time from the reception execution time is within a predetermined range from 24 hours × n (n is an integer of 1 or more) when the operation means is operated; Have
The reception control unit executes the reception process in the priority search mode when the determination unit determines that the elapsed time from the reception execution time is within a predetermined range from the 24 hours × n. A characteristic watch. The timepiece according to claim 1,
The satellite storage means includes a satellite number of the position information satellite captured by the scheduled reception process that is activated when the time counted by the timing means reaches a preset reception time, and the scheduled reception process. A first storage area for storing a scheduled reception execution time when executed;
A second storage area for storing a satellite number of the position information satellite captured by the forced reception process, which is a reception process other than the scheduled reception process, and a forced reception execution time when the forced reception process is executed. And
When the scheduled reception process is executed by the receiving unit, it is determined whether or not an elapsed time from the scheduled reception execution time is within a predetermined range from 24 hours × n (n is an integer of 1 or more). First determining means for
Second judgment means for judging whether or not an elapsed time from the forced reception execution time is within a predetermined range from the 24 hours × n when the forced reception processing is executed by the reception means; Have
The reception control unit determines that the elapsed time from the scheduled reception execution time is within a predetermined range from the 24 hours × n by the first determination unit, or the second determination unit performs the forcing A timepiece that executes reception processing in the priority search mode when it is determined that the elapsed time from the reception execution time is within a predetermined range from the 24 hours × n. The timepiece according to claim 4,
The second determination means executes the forced reception execution time stored in the second storage area and the scheduled reception execution stored in the first storage area when the forced reception processing is executed by the reception means. It is determined whether the elapsed time from the time is within a predetermined range from the 24 hours × n,
The reception control means, when the second determination means determines that the elapsed time from at least one of the forced reception execution time and the scheduled reception execution time is within a predetermined range from the 24 hours × n And a reception process in the priority search mode using the satellite number stored in the determination target storage area. The timepiece according to any one of claims 1 to 5,
The receiving means includes positioning processing means for capturing three or more position information satellites, receiving satellite signals transmitted from the position information satellites, and acquiring position information based on the satellite signals;
The timepiece characterized in that the reception control means causes the position information satellite to be searched in the fixed search mode when the positioning process by the positioning processing means is executed. The timepiece according to any one of claims 1 to 6,
The timepiece storing means stores the satellite information of the position information satellite every time the reception process is executed. Receiving means for capturing a position information satellite and receiving a satellite signal transmitted from the captured position information satellite; reception control means for controlling the receiving means to perform reception processing; time measuring means for timing time; Satellite storage means for storing the satellite number of the position information satellite captured by the reception means and the reception execution time at which the reception processing was executed, and the reception control means in the order predetermined by the reception means A satellite signal reception method for a watch, comprising: a fixed search mode for searching for the position information satellite; and a priority search mode for causing the reception means to search for a position information satellite with a satellite number stored in the satellite storage means preferentially. There,
When receiving a satellite signal transmitted from the position information satellite, one of the fixed search mode and the priority search mode according to the elapsed time from the previous reception execution time stored in the satellite storage means. And searching for the position information satellite by selecting a satellite signal.

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