JP2010085355A - Electronic apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus and a method for controlling an electronic apparatus capable of appropriate control according to battery state. <P>SOLUTION: The electronic apparatus includes: a battery 24; a GPS device 50 which is driven by power supplied from the battery 24, receives a satellite signal and performs calculation processing for acquiring satellite information from the received satellite signal; a voltage detection device 52 for detecting the output voltage from the battery 24; a load part 54 for applying, to the battery 24, a load smaller than that applied to the GPS device; a reception calculation part 50; and a controlling part 40 for controlling operation of the voltage detection part 52 and the load part 54. The controlling part 40 operates the load part 54 before power supply to the reception calculation part 50 from the battery 24, performs first voltage detection processing for detecting the output voltage from the battery 24 by the voltage detection device 52 during the operation of the load device 54 and controls operation of the GPS device 50 after the operation of the load part 54 based on the detected output voltage from the battery 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device and a method for controlling the electronic device.

  An artificial satellite (GPS satellite) orbiting the orbit above the earth transmits a radio wave superimposed with time information and orbit information, and a ground receiver (GPS receiver) receives this radio wave and measures its position. A global positioning system (GPS) is widely known.

In recent years, portable electronic devices equipped with a GPS receiver have also been developed. In such portable electronic devices, a configuration using a battery as a power source is known.
JP 2002-267734 A

  However, in a portable electronic device, it is difficult to mount a large capacity battery as a power source. For this reason, for example, if the GPS receiver starts a reception operation when the battery capacity is insufficient, the voltage necessary for the operation of the electronic device cannot be secured, and the operation of the electronic device may be defective. It was. Further, if a process with a large current consumption is performed when the battery capacity is low, the period until the battery capacity becomes insufficient is shortened.

  For this reason, a method for estimating the battery capacity before the start of the reception operation has been developed. However, since the characteristics of the battery change depending on the progress of deterioration of the battery, the ambient temperature, and the like, the method described in Patent Document 1 increases the battery capacity. It was difficult to estimate accurately.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic device and an electronic device control method capable of appropriate control according to the state of the battery.

  (1) An electronic device according to the present invention is an electronic device having a function of receiving a satellite signal transmitted from a position information satellite, and is driven by receiving power from the battery unit and the battery unit, A reception calculation unit that receives a satellite signal and performs calculation processing to acquire satellite information from the received satellite signal, a voltage detection unit that detects an output voltage of the battery unit, and the reception calculation for the battery unit A load unit that applies a lighter load than the unit, and a control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit, the control unit from the battery unit to the reception calculation unit Prior to power supply, the load unit is operated, a first voltage detection process is performed in which the voltage detection unit detects an output voltage of the battery unit during the operation of the load unit, and the first voltage detection process Of the detected battery unit Based on the force voltage, and controlling the operation of the reception operation unit after the operation of the load unit.

  The satellite information is time information held by the position information satellite, orbit information of the position information satellite, and the like.

  According to the present invention, after operating the load unit that gives a lighter load than the reception calculation unit, to control the operation of the reception calculation unit based on the output voltage of the battery unit detected during the operation of the load unit, Appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (2) In this electronic device, the control unit reduces the amount of electricity consumed per operation period of the reception calculation unit as the output voltage of the battery unit detected in the first voltage detection process is lower. In this way, the operation of the reception calculation unit may be controlled.

  In one operation period of the reception calculation unit, the calculation processing for acquiring the satellite information is completed after the reception calculation unit starts receiving the satellite signal in order to acquire the satellite information (including the case where the reception calculation unit ends due to timeout). This is the period until the operation ends.

  The amount of electricity consumed per operation period is the product of the current consumption during one operation period and the time during one operation period. Therefore, the amount of electricity consumed can be reduced by reducing the current consumption, shortening the operation period, or combining both.

  It is considered that the remaining battery capacity is smaller as the output voltage of the battery unit detected in the first voltage detection process is lower. Therefore, by controlling the operation of the reception calculation unit so that the lower the output voltage of the battery unit detected in the first voltage detection process is, the smaller the amount of electricity consumed per operation period of the reception calculation unit is. It is possible to avoid malfunctions due to insufficient capacity.

  (3) In this electronic device, the control unit performs a second voltage detection process in which the voltage detection unit detects an output voltage of the battery unit while the load unit is not operating, and the first voltage The operation of the reception calculation unit after the operation of the load unit is controlled based on the output voltage of the battery unit detected by the detection process and the second voltage detection process.

  According to the present invention, after operating the load unit that applies a lighter load than the reception calculation unit, the operation of the reception calculation unit is performed based on the output voltage of the battery unit detected during operation and non-operation of the load unit. Therefore, appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (4) In this electronic device, the control unit detects when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage or by the second voltage detection process. When the output voltage of the battery unit is lower than the second reference voltage, the difference between the output voltages of the battery unit detected by the first voltage detection process and the second voltage detection process is You may control the operation | movement of the said reception calculating part so that the amount of electricity consumed per operation | movement period of the said reception calculating part becomes so small that it is large.

  It is considered that the remaining battery capacity is smaller as the difference between the output voltages of the battery units detected in the first voltage detection process and the second voltage detection process is larger. Therefore, when the output voltage of the battery unit detected in the first voltage detection process is lower than the first reference voltage, or the output voltage of the battery unit detected in the second voltage detection process is higher than the second reference voltage. Is lower, the larger the difference between the output voltages of the battery units detected in the first voltage detection process and the second voltage detection process, the smaller the amount of electricity consumed per operation period of the reception calculation unit. As described above, by controlling the operation of the reception calculation unit, it is possible to avoid malfunctions due to insufficient battery capacity.

  (5) In this electronic device, the control unit calculates an internal resistance value of the battery unit from an output voltage of the battery unit detected by the first voltage detection process and the second voltage detection process. An internal resistance value calculation process may be performed, and the operation of the reception calculation unit after the operation of the load unit may be controlled based on the internal resistance value.

  There is a correlation between the internal resistance value of the battery unit and the deterioration of the battery capacity. Therefore, by controlling the operation of the reception calculation unit based on the internal resistance value of the battery unit, it is possible to control appropriately according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of ambient temperature, etc. become.

  (6) In this electronic device, the control unit detects when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage or by the second voltage detection process. When the output voltage of the battery unit is lower than the second reference voltage, the reception calculation is performed such that the larger the internal resistance value, the smaller the amount of electricity consumed per operation period of the reception calculation unit. The operation of the unit may be controlled.

  It is considered that the larger the internal resistance value, the more the battery deteriorates and the less the battery capacity. Therefore, when the output voltage of the battery unit detected in the first voltage detection process is lower than the first reference voltage, or the output voltage of the battery unit detected in the second voltage detection process is higher than the second reference voltage. If the internal resistance value is larger, the operation of the reception calculation unit is controlled so that the amount of electricity consumed per operation period of the reception calculation unit becomes smaller, thereby avoiding malfunctions due to insufficient battery capacity. can do.

  (7) In this electronic device, the control unit estimates the voltage of the battery unit during operation of the reception calculation unit from the internal resistance value and a load on the battery unit during operation of the reception calculation unit. The operation of the reception calculation unit after the operation of the load unit is controlled based on the output voltage of the battery unit during the operation of the reception calculation unit estimated by the estimation calculation process. Good.

  By estimating the output voltage of the battery unit during the operation of the reception calculation unit and controlling the operation of the reception calculation unit based on the value, the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature, etc. Appropriate control becomes possible according to the state of the.

  (8) In this electronic device, the control unit consumes electricity per one operation period of the reception calculation unit as the output voltage of the battery unit during operation of the reception calculation unit estimated by the estimation calculation process decreases. You may control operation | movement of the said reception calculating part so that quantity may become small.

  It is considered that the smaller the output voltage of the battery unit during the operation of the reception calculation unit estimated by the estimation calculation process, the smaller the remaining battery capacity. Therefore, the operation of the reception calculation unit is controlled such that the smaller the output voltage of the battery unit during the operation of the reception calculation unit estimated by the estimation calculation process, the smaller the amount of electricity consumed per operation period of the reception calculation unit. Thus, it is possible to avoid malfunctions due to insufficient battery capacity.

  (9) In this electronic device, the operation of the reception calculation unit includes a plurality of operation modes, and the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes. May be.

  The state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature, etc. by controlling the operation of the reception calculation unit by selecting one of a plurality of operation modes with different loads. Appropriate control becomes possible depending on the situation.

  (10) In this electronic apparatus, the operation of the reception calculation unit includes a position information acquisition mode for generating position information based on the satellite information, and a time information acquisition mode for generating time information based on the satellite information. In addition, the control unit may control the operation of the reception calculation unit by selecting from the position information acquisition mode and the time information acquisition mode.

  When operating the reception calculation unit in a position information acquisition mode that requires satellite signals from four position information satellites When operating the reception calculation unit in a time information acquisition mode that requires satellite signals from one position information satellite Current consumption is larger than Therefore, the control unit controls the operation of the reception calculation unit by selecting either the position information acquisition mode or the time information acquisition mode, thereby including the progress of deterioration of the battery unit, the influence of the ambient temperature, etc. Appropriate control is possible according to the state of the battery unit.

  (11) In this electronic device, the reception calculation unit generates positioning information by performing positioning calculation based on the satellite information until it becomes a given DOP value or less in the position information acquisition mode. Processing may be performed, and the control unit may control the operation of the reception calculation unit by changing the given DOP value.

  Since it takes time to perform the positioning calculation until the DOP value decreases, the current consumption increases. Therefore, by changing a given DOP value, appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (12) In this electronic device, the reception calculation unit performs satellite search processing for searching for the position information satellite within a given search time limit based on the satellite signal, and the control unit performs the reception calculation. The operation of the unit may be controlled by changing the given search time limit.

  If the satellite search process cannot be completed within a given search time limit, the satellite search process is terminated (time-out process). For example, in an environment where the reception state is bad, a time-out process is performed because the satellite search process cannot be completed within a given search time limit. When the time until the timeout process becomes longer, the current consumption increases. Therefore, by changing the given search time limit, appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (13) In this electronic device, the control unit controls the operation of the reception calculation unit by changing a calculation time limit for performing calculation processing for acquiring satellite information from the satellite signal received by the reception calculation unit. May be.

  If the calculation process cannot be completed within the calculation time limit, the calculation process ends (timeout process). For example, in an environment where the reception state is bad, a timeout process is performed because the calculation process cannot be completed within the calculation time limit. When the time until the timeout process becomes longer, the current consumption increases. Therefore, by changing the calculation time limit, appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (14) In this electronic device, the control unit may control the operation of the reception calculation unit by selecting whether to operate the reception calculation unit after the operation of the load unit.

  For example, when the battery capacity is low, it is possible to avoid malfunctions due to insufficient battery capacity by selecting not to operate the reception calculation unit.

  (15) The electronic device may include a timer unit that holds internal time information, and the control unit may correct the internal time information based on the satellite information acquired by the reception calculation unit.

  The internal time information is time information measured inside the electronic device.

  By correcting the internal time information based on the satellite information, an electronic device that retains accurate internal time information can be realized.

  (16) An electronic device control method according to the present invention is an electronic device having a function of receiving a satellite signal transmitted from a position information satellite, and is driven by receiving power from the battery unit and the battery unit. And receiving the satellite signal, performing a calculation process for acquiring satellite information from the received satellite signal, a voltage detection unit for detecting an output voltage of the battery unit, and the battery unit, A control method for an electronic device including a load unit that applies a lighter load than the reception calculation unit, and a control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit, wherein the control unit includes: A step of operating the load unit prior to power supply from the battery unit to the reception operation unit; and a first voltage for detecting an output voltage of the battery unit during operation of the load unit by the voltage detection unit. Perform detection processing And a step of controlling the operation of the reception calculation unit after the operation of the load unit based on the output voltage of the battery unit detected in the first voltage detection process. .

  According to the present invention, after operating the load unit that gives a lighter load than the reception calculation unit, to control the operation of the reception calculation unit based on the output voltage of the battery unit detected during the operation of the load unit, Appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  (17) An electronic device control method according to the present invention is an electronic device having a function of receiving a satellite signal transmitted from a position information satellite, and is driven by receiving power from the battery unit and the battery unit. And receiving the satellite signal, performing a calculation process for acquiring satellite information from the received satellite signal, a voltage detection unit for detecting an output voltage of the battery unit, and the battery unit, A control method for an electronic device including a load unit that applies a lighter load than the reception calculation unit, and a control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit, wherein the control unit includes: A step of operating the load unit prior to power supply from the battery unit to the reception calculation unit; and a first voltage for detecting an output voltage of the battery unit during operation of the load unit by the voltage detection unit. Detection process, A step of performing a second voltage detection process in which the voltage detection unit detects an output voltage of the battery unit while the load unit is not in operation; the first voltage detection process and the second voltage detection process; And the step of controlling the operation of the reception calculation unit after the operation of the load unit based on the output voltage of the battery unit detected in (1).

  According to the present invention, after operating the load unit that applies a lighter load than the reception calculation unit, the operation of the reception calculation unit is performed based on the output voltage of the battery unit detected during operation and non-operation of the load unit. Therefore, appropriate control can be performed according to the state of the battery unit including the progress of deterioration of the battery unit and the influence of the ambient temperature.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. GPS system 1-1. Outline FIG. 1 is a diagram for explaining an outline of a GPS system.

  The GPS satellite 10 orbits a predetermined orbit above the earth and transmits a navigation message superimposed on a 1.57542 GHz radio wave (L1 wave) to the ground. Here, the GPS satellite 10 is an example of a position information satellite in the present invention, and a 1.57542 GHz radio wave (hereinafter referred to as “satellite signal”) on which a navigation message is superimposed is an example of a satellite signal in the present invention.

  Currently, there are about 30 GPS satellites 10, and in order to identify which GPS satellite 10 the satellite signal is transmitted from, each GPS satellite 10 is 1023 chip called C / A code (Coarse / Acquisition Code) A unique pattern of (1 ms period) is superimposed on the satellite signal. The C / A code looks like a random pattern with each chip being either +1 or -1. 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 10 is equipped with an atomic clock, and the satellite signal includes extremely accurate time information (hereinafter referred to as “GPS time information”) measured by the atomic clock. Further, a slight time error of the atomic clock mounted on each GPS satellite 10 is measured by a control segment on the ground, and the satellite signal includes a time correction parameter for correcting the time error. Therefore, the GPS receiver 1 can receive a satellite signal transmitted from one GPS satellite 10 and correct the internal time to an accurate time using GPS time information and time correction parameters included therein. it can.

  The satellite signal includes orbit information indicating the position of the GPS satellite 10 on the orbit. The GPS receiver 1 can perform positioning calculation using GPS time information and orbit information. The positioning calculation is performed on the assumption that a certain amount of error is included in the internal time of the GPS receiver 1. That is, in addition to the x, y, and z parameters for specifying the three-dimensional position of the GPS receiver 1, the time error is also an unknown. Therefore, the GPS receiver 1 generally receives satellite signals respectively transmitted from four or more GPS satellites, and performs positioning calculation using GPS time information and orbit information included therein.

1-2. Navigation Message FIGS. 2A to 2C are diagrams for explaining the configuration of the navigation message.

  As shown in FIG. 2 (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 10 in 6 seconds. Therefore, data of one main frame is transmitted from each GPS satellite 10 in 30 seconds.

  Subframe 1 includes satellite correction data such as week number data (WN). 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.

  The subframes 2 and 3 include ephemeris parameters (detailed orbit information of each GPS satellite 10). Further, the subframes 4 and 5 include almanac parameters (schematic orbit information of all GPS satellites 10).

  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 device satellite 10 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. 2B, the TLM word includes preamble data, a TLM message, a reserved bit, and parity data.

  As shown in FIG. 2C, the HOW word includes 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 seconds indicated every week from the beginning of the week, and the elapsed time is a number expressed in units of 1.5 seconds. Here, the Z count data indicates time information at which the first bit of the next subframe data is transmitted. For example, the Z count data of subframe 1 indicates 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 1 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 1 has previously acquired week number data and is counting the elapsed time since the time when the week number data was acquired internally, the GPS receiver 1 does not have to acquire the week number data. Current week number data can be obtained. Therefore, if the GPS receiver 1 acquires the Z count data, the current GPS time information can be roughly estimated. For this reason, the GPS receiver 1 normally acquires only Z count data as time information.

  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.

  As the GPS receiver 1, for example, a wristwatch with a GPS device (hereinafter referred to as “GPS wristwatch”) can be considered. A GPS wristwatch is an example of an electronic apparatus according to the present invention, and the GPS wristwatch according to the present embodiment will be described below.

2. 2. Watch with GPS 2-1. First Embodiment [GPS Watch Structure]
FIG. 3A and FIG. 3B are diagrams for explaining the structure of the GPS wristwatch according to the first embodiment. FIG. 3A is a schematic plan view of a GPS wristwatch, and FIG. 3B is a schematic cross-sectional view of the GPS wristwatch of FIG.

  As shown in FIG. 3A, the GPS wristwatch 1 includes a dial 11 and hands 12. A display 13 is incorporated in an opening formed in a part of the dial 11. The display 13 is composed of an LCD (Liquid Crystal Display) display panel or the like, and displays information such as the current longitude and latitude, the city name of the current location, and various message information. The pointer 12 includes a second hand, a minute hand, an hour hand, and the like, and is driven by a step motor via a gear.

  The GPS wristwatch 1 has a mode (time information acquisition mode) and a mode in which a satellite signal from at least one GPS satellite 10 is received and internal time information is corrected by manually operating the crown 14 and buttons 15 and 16. It is configured to be able to set to a mode (position information acquisition mode) for receiving a satellite signal from the GPS satellite 10 and performing a positioning calculation to correct the time difference of the internal time information. The GPS wristwatch 1 can also execute the time information acquisition mode and the position information acquisition mode periodically (automatically).

  As shown in FIG. 3B, the GPS wristwatch 1 includes an outer case 17 made of a metal such as stainless steel (SUS) or titanium.

  The exterior case 17 is formed in a substantially cylindrical shape, and a surface glass 19 is attached to the opening on the surface side via a bezel 18. A back cover 26 is attached to the opening on the back side of the outer case 17. The back cover 26 is formed of a metal in a ring shape, and a back glass 23 is attached to the central opening.

  Inside the outer case 17, a step motor for driving the pointer 12, a GPS antenna 27, a battery 24, and the like are arranged.

  The step motor includes a motor coil 20, a stator, a rotor, and the like, and drives the pointer 12 via a gear.

  The GPS antenna 27 is an antenna that receives satellite signals from a plurality of GPS satellites 10, and is realized by a patch antenna, a helical antenna, a chip antenna, or the like. The GPS antenna 27 is disposed on the surface (back side) opposite to the time display surface of the dial plate 11 and receives satellite signals that have passed through the front glass 19 and the dial plate 11. Therefore, the dial plate 11 and the surface glass 19 are made of a material that transmits radio waves in the 1.5 GHz band, for example, plastic. The bezel 18 is made of ceramic or the like that is less deteriorated in receiving performance than a metal member.

  A circuit board 25 is disposed on the back cover side of the GPS antenna 27, and a battery 24 is disposed on the back cover side of the circuit board 25.

  The circuit board 25 is provided with a receiving IC 30 including a receiving circuit for processing a satellite signal received by the GPS antenna 27, a control IC 40 for performing drive control of a step motor, and the like. The reception IC 30 and the control IC 40 are driven by electric power supplied from the battery 24.

  The battery 24 is a rechargeable secondary battery such as a lithium ion battery, and the magnetic sheet 21 is disposed on the lower side (back cover side) of the battery 24. A charging coil 22 is arranged via the magnetic sheet 21, and the battery 24 can be charged with electric power from an external charger by electromagnetic induction.

  Further, the magnetic sheet 21 can bypass the magnetic field. Therefore, the magnetic sheet 21 can reduce the influence of the battery 24 and perform energy transmission efficiently. A back glass 23 is disposed at the center of the back cover 26 for power transfer.

  In the present embodiment, a secondary battery such as a lithium ion battery is used as the battery 24, but a primary battery such as a lithium battery may be used. In addition, the charging method in the case where a secondary battery is provided is not limited to the charging method provided by the charging coil 22 and charging by an electromagnetic induction method from an external charger as in the present embodiment. You may charge by providing electric power generation mechanisms, such as a solar cell.

[Circuit configuration of GPS wristwatch]
FIG. 4 is a diagram for explaining a circuit configuration of the GPS wristwatch according to the first embodiment.

  The GPS wristwatch 1 according to the present embodiment includes a CPU (control IC) 40, a RAM 42, a ROM 44, an input device 46, a display device 48, a GPS device 50, a battery 24, a voltage detection device 52, connected to a bus 32. The load device 54 and the time measuring device 56 can be included.

  The CPU 40 controls operations of various devices connected to the bus 32. The CPU 40 corresponds to the control unit in the present invention.

  The RAM 42 temporarily stores data necessary for controlling operations of various devices performed by the CPU 40.

  The ROM 44 stores programs and data necessary for controlling operations of various devices performed by the CPU 40.

  The input device 46 receives an operation from the outside of the GPS wristwatch 1. The input device 46 is a device that accepts user operations on the crown 14, button 15, and button 16 in FIG.

  The display device 48 displays various information and messages such as time, greatness, and longitude. The display device 48 is, for example, a device such as the dial plate 11, the hands 12, and the display 13 in FIG.

  The battery 24 supplies driving power to various devices connected to the bus 18. The voltage may be changed by a regulator (not shown) to supply the driving power as required by the device that receives the driving power. The battery 24 is configured to be controllable by the CPU 40 as to whether or not driving power is supplied to the GPS device 50. The battery 24 corresponds to the battery unit in the present invention.

  The voltage detection device 52 detects the output voltage of the battery 24. The detected output voltage is configured to be acquired by the CPU 40. The voltage detection device 52 corresponds to the voltage detection unit in the present invention.

  The load device 54 gives a lighter load to the battery 24 than when the GPS device 50 is operating. The load device 54 corresponds to a load unit in the present invention.

  FIG. 5 is a diagram for explaining a circuit configuration example of the load device 54.

  The load device 54 in the present embodiment is configured with a resistor. The resistance value may be set to a value at which a current that is about 1/10 of a current that flows when the GPS device 50 is operated, for example. For example, when the load during operation of the GPS device 50 corresponds to 100Ω, the resistance value may be set to 1 kΩ.

  One end of the resistor constituting the load device 54 is connected to the positive electrode of the battery 24 via the switch 53, and the other end of the resistor constituting the load device 54 is connected to the negative electrode of the battery 24.

  The switch 53 switches between three modes: a mode in which driving power from the battery 24 is supplied to the GPS device 50, a mode in which the driving power is supplied to the load device 54, and a mode in which neither of the GPS device 50 nor the load device 54 is supplied. . The CPU 40 switches the switch 53 according to the control signal 40A.

  The CPU 40 operates by receiving drive power from the battery 24. The battery 24 supplies driving power to the RAM 42, the ROM 44, the input device 46, the display device 48, the voltage detection device 52, and the time measuring device 56 shown in FIG.

  The timing device 56 in the circuit configuration shown in FIG. 4 measures and stores internal time information. The time measuring device 56 can be composed of, for example, a crystal resonator, an oscillation circuit, a RAM that stores internal time information, a drive circuit for driving the display device 48, and the like. The internal time information is updated by a reference clock signal generated by the crystal resonator and the oscillation circuit.

  The GPS device 50 in the circuit configuration shown in FIG. 4 receives a satellite signal, searches for a GPS satellite 10, generates position information, generates time correction information, and sets a search time limit that is a time limit for searching for a GPS satellite. Process. The GPS device 50 corresponds to the reception calculation unit in the present invention.

[Configuration of GPS device]
The GPS device 50 can include, for example, a GPS antenna 27 and a SAW (Surface Acoustic Wave) filter (not shown). The GPS antenna 27 is an antenna that receives satellite signals from a plurality of GPS satellites 10 as described with reference to FIG. However, the GPS antenna 27 also receives signals other than satellite signals. The SAW filter performs a process of extracting a satellite signal from the signal received by the GPS antenna 27. That is, the SAW filter is configured as a bandpass filter that passes a 1.5 GHz band signal.

  The GPS device 50 can be configured to include, for example, a receiving IC (receiving circuit) 30. The receiving circuit 30 can be configured to include, for example, an RF (Radio Frequency) unit and a baseband unit. As will be described below, the receiving circuit 30 performs processing for acquiring satellite information such as orbit information and GPS time information included in the navigation message from a 1.5 GHz band satellite signal extracted by the SAW filter.

  The above-described RF unit includes, for example, an LNA (Low Noise Amplifier), a mixer, a VCO (Voltage Controlled Oscillator), a PLL (Phase Locked Loop) circuit, an IF amplifier, an IF (Intermediate Frequency) filter, and an ADC (A / D). Converter) and the like. An example of the operation of the RF unit in this case will be briefly described.

  The satellite signal extracted by the SAW filter is amplified by the LNA. The satellite signal amplified by the LNA is mixed with the clock signal output from the VCO by the mixer and down-converted to an intermediate frequency band signal. The PLL circuit compares the phase of the clock signal obtained by dividing the output clock signal of the VCO with the reference clock signal, and synchronizes the output clock signal of the VCO with the reference clock signal. As a result, the VCO 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 is amplified by the IF amplifier. Here, a high frequency signal of several GHz is generated together with the signal in the intermediate frequency band by mixing in the mixer. Therefore, the IF amplifier amplifies a high frequency signal of several GHz together with the signal in the intermediate frequency band. The IF filter passes the signal in the intermediate frequency band and removes the high frequency signal of several GHz (precisely, attenuates below a predetermined level). The intermediate frequency band signal that has passed through the IF filter is converted into a digital signal by an ADC (A / D converter).

  The above-described baseband unit includes, for example, a DSP (Digital Signal Processor), a CPU (Central Processing Unit), an SRAM (Static Random Access Memory), an RTC (Real Time Clock), a temperature-compensated crystal oscillation circuit (TCXO: Temperature Compensated Crystal). Oscillator), flash memory, etc. can be included.

  A crystal oscillation circuit (TCXO) with a temperature compensation circuit generates a reference clock signal having a substantially constant frequency regardless of the temperature.

  For example, time difference information is stored in the flash memory. The time difference information is information in which time difference data (such as a correction amount for UTC associated with coordinate values (for example, latitude and longitude)) is defined.

  When set to the time information acquisition mode or the position information acquisition mode, the baseband unit performs a process of demodulating the baseband signal from the digital signal (intermediate frequency band signal) converted by the ADC of the RF unit.

  The operation of the baseband unit is synchronized with the reference clock signal output from the above-described crystal oscillation circuit with temperature compensation circuit (TCXO). The RTC described above generates timing for processing satellite signals. This RTC is counted up by the reference clock signal output from the TCXO.

[Operation of GPS device]
When set to the time information acquisition mode or the position information acquisition mode, the GPS device 50 generates a local code having the same pattern as each C / A code in a satellite search process described later, and includes each of the codes included in the baseband signal Processing for correlating the C / A code and the local code is performed. Then, the GPS device 50 adjusts the local code generation timing so that the correlation value for each local code becomes a peak, and if the correlation value is equal to or greater than the threshold value, it synchronizes with the GPS satellite 10 of the local code (that is, It is determined that the GPS satellite 10 has been captured). Here, the GPS system employs a CDMA (Code Division Multiple Access) system in which all GPS satellites 10 transmit satellite signals of the same frequency using different C / A codes. Therefore, it is possible to search for a GPS satellite 10 that can be captured by determining the C / A code included in the received satellite signal.

  Further, the GPS device 50 acquires a local code and a base of the same pattern as the C / A code of the GPS satellite 10 in order to acquire the satellite information of the captured GPS satellite 10 in the time information acquisition mode or the position information acquisition mode. Performs processing to mix band signals. In the mixed signal, a navigation message including satellite information of the captured GPS satellite 10 is demodulated. Then, the GPS device 50 detects the TLM word (preamble data) of each subframe of the navigation message, and acquires satellite information such as orbit information and GPS time information included in each subframe (for example, stored in the above-described SRAM). Process). Here, the GPS time information is the week number data (WN) and the Z count data, but may be only the Z count data when the week number data has been acquired previously.

  Then, the GPS device 50 acquires time information (GPS time information) based on the satellite information, and generates time correction information necessary for correcting the internal time information.

  In the time information acquisition mode, more specifically, the GPS device 50 performs time measurement calculation based on the GPS time information and generates time correction information. The time correction information in the time information acquisition mode may be, for example, GPS time information itself or information on a time difference between the GPS time information and the internal time information.

  On the other hand, in the position information acquisition mode, more specifically, the GPS device 50 performs positioning calculation based on GPS time information and orbit information, and the position of the position information (more specifically, the GPS wristwatch 1 Get the latitude and longitude of the location. Further, the GPS device 50 refers to the time difference information stored in the flash memory described above, and acquires time difference data associated with the coordinate values (for example, latitude and longitude) of the GPS wristwatch 1 specified by the position information. To do. In this way, the GPS device 50 generates GPS time information and time difference data as time correction information. As described above, the time correction information in the position information acquisition mode may be the GPS time information and the time difference data itself. For example, instead of the GPS time information, the time correction information is a time difference data between the internal time information and the GPS time information. Also good.

  The GPS device 50 may generate time correction information from the satellite information of one GPS satellite 10 or may generate time correction information from the satellite information of a plurality of GPS satellites 10.

[Control of operation of reception calculation unit by control unit]
Hereinafter, control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the first embodiment will be described. In this embodiment, the operation of the reception calculation unit includes a plurality of operation modes, and an example in which the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes will be described.

  Further, in the following description, the operation mode of the reception calculation unit with the relatively large amount of electricity consumed per operation period of the reception calculation unit is “A mode”, and the power consumption per operation period of the reception calculation unit. The operation mode of the reception calculation unit with the smaller amount is “B mode”, and the operation mode of the reception calculation unit when driving power is not supplied to the reception calculation unit (when the reception calculation unit is not operated) is “C mode”. " Details of an operation example of the reception calculation unit in the “A mode” and the “B mode” will be described later. For convenience of explanation, the case where the reception arithmetic unit is not operated is expressed as “operate in“ C mode (do not operate) ””.

  In one operation period of the reception calculation unit, the calculation processing for acquiring the satellite information is completed after the reception calculation unit starts receiving the satellite signal in order to acquire the satellite information (including the case where the reception calculation unit ends due to timeout). This is a period until the operation is finished (hereinafter, the same applies to other embodiments).

  FIG. 6 is a flowchart for explaining the control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the first embodiment.

  FIG. 7 is a graph showing changes in the output voltage of the battery unit (battery 24) when the load unit (load device 54) is operating and when the reception calculation unit (GPS device 50) is operating. The horizontal axis represents time with reference to the start of operation of the load unit (load device 54). The vertical axis represents the output voltage of the battery unit (battery 24).

  In FIG. 7, the change in the output voltage of the battery unit (battery 24) during operation of the load unit (load device 54) is indicated by a solid line, and the battery unit (when the reception calculation unit (GPS device 50) is operated in the “A mode” ( The change in the output voltage of the battery 24) is indicated by a broken line.

  The CPU 40 determines whether or not there is a request for driving the GPS device 50 (GPS drive request) (step S10). The CPU 40 may itself generate a GPS drive request at periodic timing (for example, every 24 hours). In addition, the CPU 40 may determine that a GPS driving request has been made at a timing when the input device 46 receives an operation of a specific user.

  If it is determined in step S10 that there is no GPS drive request, the CPU 40 waits for a predetermined time (step S12), and repeats steps S10 and S12 until there is a GPS drive request.

  If it is determined in step S10 that a GPS drive request has been made, the CPU 40 drives the load device 54 for a given time prior to supplying power to the GPS device 50 (step S14). In the circuit diagram shown in FIG. 5, the load device 54 is driven by connecting the switch 53 to the load device 54 side based on the control signal 40A. The given time is a time until the output voltage of the battery 24 is stabilized to some extent, and may be, for example, about 5 seconds.

  Next, the CPU 40 detects the output voltage of the battery 24 during the operation of the load device 54 by the voltage detection device 52, and performs a first voltage detection process to be acquired (step S16). While the load device 54 is operating, the output voltage of the battery 24 is lower than when the load device 54 is not operating.

  In the solid line graph of FIG. 7, the period from time −5 seconds to 0 seconds is a period in which the load device 54 is not operating, and the operation of the load device 54 is started at time 0 seconds, and then the time 6 seconds. The period until is a period during which the load device 54 is operating. When the load device 54 is not operating, the output voltage of the battery 24 is Vo (about 4.1 V in the graph of FIG. 7). During operation of the load device 54, the output voltage of the battery 24 is Vc (about 3.95 V in the graph of FIG. 7). Since the load of the load device 54 is lighter than that of the GPS device 50, the output voltage Vc is higher than the output voltage Vca of the battery 24 when the GPS device 50 described later is in operation.

  A graph when the GPS device 50 is operated in the “A mode” instead of the load device 54 is a broken line graph in FIG. 7. In the broken line graph of FIG. 7, the period from time −5 seconds to 0 seconds is a period in which the GPS device 50 is not operating, the operation of the GPS device 50 is started at time 0 seconds, and the subsequent period is This is a period during which the GPS device 50 is operating. When the GPS device 50 is not operating, the output voltage of the battery 24 is Vo (about 4.1 V in the graph of FIG. 7). When the GPS device 50 is in operation, the output voltage of the battery 24 is Vca (about 3.25 V in the graph of FIG. 7).

  After a predetermined time has elapsed from step S14, the CPU 40 finishes driving the load device 54 (step S18). In the circuit diagram shown in FIG. 5, the driving of the load device 54 is terminated by disconnecting the switch 53 from the load device 54 based on the control signal 40A.

  Next, the CPU 40 determines whether or not the output voltage Vc of the battery 24 detected in the first voltage detection process (step S16) is equal to or higher than the threshold voltage Vtha (step S20).

  When the output voltage Vc is equal to or higher than the threshold voltage Vtha, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S24). In this case, if the drive request received in step S10 is “A mode”, the CPU 40 causes the GPS device 50 to operate in “A mode”. If the drive request received in step S10 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  In step S20, if the output voltage Vc is less than the threshold voltage Vtha, the CPU 40 determines whether or not the output voltage Vc of the battery 24 detected in the first voltage detection process (step S16) is equal to or higher than the threshold voltage Vthb. Is determined (step S22).

  When the output voltage Vc is equal to or higher than the first threshold voltage Vtha, the CPU 40 is permitted to operate the GPS device 50 in “B mode” or “C mode (not operated)” (step S26). In this case, if the drive request received in step S10 is “A mode”, the CPU 40 operates the GPS device 50 in “B mode” or “C mode (not operated)”. If the drive request received in step S10 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  If the output voltage Vc is less than the threshold voltage Vthb in step S22, the CPU 40 operates the GPS device 50 in “C mode (do not operate)” (step S28). In this case, the CPU 40 operates the GPS device 50 in the “C mode (do not operate)” regardless of whether the drive request received in step S10 is “A mode” or “B mode”.

  As the threshold voltage Vtha, for example, a voltage that can be determined to have sufficient battery capacity even when the GPS device 50 operates in the “A mode” is set. In the graph of FIG. 7, the threshold voltage Vtha is set to about 4V.

  As the threshold voltage Vthb, for example, a voltage that can be determined to have sufficient battery capacity even when the GPS device 50 operates in the “B mode” is set. In the graph of FIG. 7, the threshold voltage Vthb is set to about 3.7V.

  In the example of the graph of FIG. 7, the output voltage Vc is not less than the threshold voltage Vthb and less than the threshold voltage Vtha. Therefore, the CPU 40 is permitted to operate the GPS device 50 in the “B mode”.

  According to the first embodiment, after the load device 54 that applies a lighter load than the GPS device 50 is operated, the operation of the GPS device 50 is performed based on the output voltage Vc of the battery 24 detected during the operation of the load device 54. Therefore, appropriate control can be performed according to the state of the battery 24 including the progress of deterioration of the battery 24 and the influence of the ambient temperature.

  In addition, it is considered that the lower the output voltage Vc of the battery 24 detected in the first voltage detection process, the smaller the remaining battery capacity. Therefore, by controlling the operation of the GPS device 50 such that the lower the output voltage Vc of the battery 24 detected in the first voltage detection process is, the smaller the amount of electricity consumed per operation period of the reception calculation unit is. A malfunction of the GPS wristwatch due to insufficient battery capacity can be avoided.

2-2. Second Embodiment The structure and circuit configuration of the GPS wristwatch according to the second embodiment are the same as the structure and circuit configuration of the GPS wristwatch according to the first embodiment shown in FIGS. To do.

[Control of operation of reception calculation unit by control unit]
Hereinafter, control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the second embodiment will be described. In this embodiment, the operation of the reception calculation unit includes a plurality of operation modes, and an example in which the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes will be described.

  Further, in the following description, the operation mode of the reception calculation unit with the relatively large amount of electricity consumed per operation period of the reception calculation unit is “A mode”, and the power consumption per operation period of the reception calculation unit. The operation mode of the reception calculation unit with the smaller amount is “B mode”, and the operation mode of the reception calculation unit when driving power is not supplied to the reception calculation unit (when the reception calculation unit is not operated) is “C mode”. " Details of an operation example of the reception calculation unit in the “A mode” and the “B mode” will be described later. For convenience of explanation, the case where the reception arithmetic unit is not operated is expressed as “operate in“ C mode (do not operate) ””.

  FIG. 8 is a flowchart for explaining the control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the second embodiment.

  The CPU 40 determines whether or not there is a request for driving the GPS device 50 (GPS drive request) (step S30). The CPU 40 may itself generate a GPS drive request at periodic timing (for example, every 24 hours). In addition, the CPU 40 may determine that a GPS driving request has been made at a timing when the input device 46 receives an operation of a specific user.

  If it is determined in step S30 that there is no GPS drive request, the CPU 40 waits for a predetermined time (step S32) and repeats steps S30 and S32 until a GPS drive request is received.

  If it is determined in step S30 that a GPS drive request has been made, the output voltage of the battery 24 when the load device 54 is not operating is detected by the voltage detection device 52, and a second voltage detection process to be acquired is performed ( Step S34).

  The second voltage detection process (step S34) is replaced between step S30 and driving of the load device 54 described later (step S36), and driving end of the load device 54 described later (step S40) and thereafter You may perform between determination (step S42).

  Next, prior to supplying power to the GPS device 50, the CPU 40 drives the load device 54 for a given time (step S36). In the circuit diagram shown in FIG. 5, the load device 54 is driven by connecting the switch 53 to the load device 54 side based on the control signal 40A. The given time is a time until the output voltage of the battery 24 is stabilized to some extent, and may be, for example, about 5 seconds.

  Next, the CPU 40 detects the output voltage of the battery 24 during the operation of the load device 54 by the voltage detection device 52, and performs a first voltage detection process to be acquired (step S38). While the load device 54 is operating, the output voltage of the battery 24 is lower than when the load device 54 is not operating.

  After a predetermined time has elapsed from step S36, the CPU 40 ends the driving of the load device 54 (step S40). In the circuit diagram shown in FIG. 5, the driving of the load device 54 is terminated by disconnecting the switch 53 from the load device 54 based on the control signal 40A.

  Next, the CPU 40 determines whether or not the output voltage Vc of the battery 24 detected in the first voltage detection process (step S38) is equal to or higher than the first reference voltage Vth1 (step S42). For example, the first reference voltage Vth1 is set to a voltage at which it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “A mode”.

  When the output voltage Vc is equal to or higher than the first reference voltage Vth1, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S48). In this case, if the drive request received in step S30 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S30 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the output voltage Vc is less than the first reference voltage Vth1, the CPU 40 detects the output voltage Vo of the battery 24 detected in the second voltage detection process (step S34) and the first voltage detection process (step S38). It is determined whether or not the difference voltage Vd from the output voltage Vc of the battery 24 detected in step S is equal to or lower than the threshold voltage Vtd1 (step S44).

  When the difference voltage Vd is equal to or lower than the threshold voltage Vtd1, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S48). In this case, if the drive request received in step S30 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S30 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  If the difference voltage Vd exceeds the threshold voltage Vtd1 in step S42, the CPU 40 determines whether or not the difference voltage Vd is equal to or lower than the threshold voltage Vtd2 (step S46). Note that threshold voltage Vtd2> threshold voltage Vtd1.

  When the difference voltage Vd is equal to or lower than the threshold voltage Vtd2, the CPU 40 is permitted to operate the GPS device 50 in the “B mode” or the “C mode (do not operate)” (step S50). In this case, if the drive request received in step S30 is “A mode”, the CPU 40 operates the GPS device 50 in “B mode” or “C mode (not operated)”. If the drive request received in step S30 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the difference voltage Vd exceeds the threshold voltage Vtd2 in step S46, the CPU 40 operates the GPS device 50 in the “C mode (do not operate)” (step S52). In this case, regardless of whether the drive request received in step S30 is “A mode” or “B mode”, the CPU 40 causes the GPS device 50 to operate in “C mode (do not operate)”.

  As the threshold voltage Vtd1, for example, a voltage that can be determined to have sufficient battery capacity even when the GPS device 50 operates in the “A mode” is set.

  As the threshold voltage Vtd2, for example, a voltage that can be determined to have sufficient battery capacity even when the GPS device 50 operates in the “B mode” is set.

  According to the second embodiment, after the load device 54 that applies a lighter load than the GPS device 50 is operated, the output voltage Vc of the battery 24 detected during the operation of the load device 54 and the load device 54 not operating. In order to control the operation of the GPS device 50 based on the output voltage Vo of the battery 24 detected at the time, appropriate control is performed according to the state of the battery 24 including the progress of deterioration of the battery 24 and the influence of the ambient temperature, etc. Is possible.

  Further, it is considered that the remaining battery capacity decreases as the differential voltage Vd increases. Therefore, when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage, the larger the difference voltage Vd is, the more electricity is consumed per operation period of the reception calculation unit. By controlling the operation of the GPS device 50 so as to be reduced, it is possible to avoid malfunctions of the GPS wristwatch due to insufficient battery capacity.

[Modification]
In the second embodiment described above, when the output voltage of the battery unit detected in the first voltage detection process is lower than the first reference voltage, the larger the difference voltage Vd, the one operation period of the reception calculation unit. In this example, the operation of the GPS device 50 is controlled so that the amount of electricity consumed per unit is small. However, when the output voltage of the battery unit detected by the second voltage detection process is lower than the second reference voltage. May control the operation of the GPS device 50 such that the larger the difference voltage Vd, the smaller the amount of electricity consumed per operation period of the reception calculation unit.

  FIG. 9 is a flowchart for explaining a modified example of the operation control of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the second embodiment. Note that the same processes as those in the second embodiment described above are denoted by the same reference numerals as those in the flowchart of FIG. 8, and detailed description thereof will be omitted.

  The voltage detection device 52 detects the output voltage of the battery 24 when the load device 54 is not operating from the step (step S30) in which the CPU 40 determines whether or not there is a request to drive the GPS device 50 (GPS drive request). The operation until the second voltage detection process to be acquired (step S34) is the same as that of the second embodiment.

  Next, the CPU 40 determines whether or not the output voltage Vo of the battery 24 detected in the second voltage detection process (step S34) is equal to or higher than the second reference voltage Vth2 (step S54). For example, the second reference voltage Vth2 is set to a voltage at which it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “A mode”.

  When the output voltage Vo is equal to or higher than the second reference voltage Vth2, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S48). In this case, if the drive request received in step S30 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S30 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the output voltage Vo is less than the second reference voltage Vth2, the CPU 40 drives the load device 54 for a given time prior to supplying power to the GPS device 50 (step S36). Thereafter, the first voltage detection process is performed (step S38), and the operation until the driving of the load device 54 is ended (step S40) is the same as that in the second embodiment.

  After the driving of the load device 54 is completed (step S40), the CPU 40 detects the output voltage Vo of the battery 24 detected in the second voltage detection process (step S34) and the first voltage detection process (step S38). It is determined whether or not the difference voltage Vd from the output voltage Vc of the battery 24 is equal to or lower than the threshold voltage Vtd1 (step S44). The subsequent operation is the same as that of the second embodiment described above.

  As described above, when the output voltage of the battery unit detected in the second voltage detection process is lower than the second reference voltage, the larger the difference voltage Vd is, the more electricity consumed per operation period of the reception calculation unit. By controlling the operation of the GPS device 50 so as to reduce the amount, it is possible to avoid malfunctions of the GPS wristwatch due to insufficient battery capacity.

2-3. Third Embodiment The structure and circuit configuration of the GPS wristwatch according to the third embodiment are the same as the structure and circuit configuration of the GPS wristwatch according to the first embodiment shown in FIGS. To do.

[Control of operation of reception calculation unit by control unit]
Hereinafter, control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the third embodiment will be described. In this embodiment, the operation of the reception calculation unit includes a plurality of operation modes, and an example in which the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes will be described.

  Further, in the following description, the operation mode of the reception calculation unit with the relatively large amount of electricity consumed per operation period of the reception calculation unit is “A mode”, and the power consumption per operation period of the reception calculation unit. The operation mode of the reception calculation unit with the smaller amount is “B mode”, and the operation mode of the reception calculation unit when driving power is not supplied to the reception calculation unit (when the reception calculation unit is not operated) is “C mode”. " Details of an operation example of the reception calculation unit in the “A mode” and the “B mode” will be described later. For convenience of explanation, the case where the reception arithmetic unit is not operated is expressed as “operate in“ C mode (do not operate) ””.

  FIG. 10 is a flowchart for explaining the control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the third embodiment.

  The CPU 40 determines whether or not there is a request for driving the GPS device 50 (GPS drive request) (step S60). The CPU 40 may itself generate a GPS drive request at periodic timing (for example, every 24 hours). In addition, the CPU 40 may determine that a GPS driving request has been made at a timing when the input device 46 receives an operation of a specific user.

  If it is determined in step S60 that there is no GPS drive request, the CPU 40 waits for a predetermined time (step S62), and repeats steps S60 and S62 until there is a GPS drive request.

  If it is determined in step S60 that a GPS drive request has been made, the output voltage of the battery 24 when the load device 54 is not operating is detected by the voltage detection device 52, and a second voltage detection process to be acquired is performed ( Step S64).

  The second voltage detection process (step S64) is replaced between step S60 and driving of the load device 54 described later (step S66), and driving end of the load device 54 described later (step S70) and internal resistance are replaced. You may perform between value calculation processing (step S72).

  Next, prior to supplying power to the GPS device 50, the CPU 40 drives the load device 54 for a given time (step S66). In the circuit diagram shown in FIG. 5, the load device 54 is driven by connecting the switch 53 to the load device 54 side based on the control signal 40A. The given time is a time until the output voltage of the battery 24 is stabilized to some extent, and may be, for example, about 5 seconds.

  Next, the CPU 40 detects the output voltage of the battery 24 during the operation of the load device 54 by the voltage detection device 52 and performs a first voltage detection process to be acquired (step S68). While the load device 54 is operating, the output voltage of the battery 24 is lower than when the load device 54 is not operating.

  After a given time has elapsed from step S66, the CPU 40 finishes driving the load device 54 (step S70). In the circuit diagram shown in FIG. 5, the driving of the load device 54 is terminated by disconnecting the switch 53 from the load device 54 based on the control signal 40A.

  Next, the CPU 40 determines whether or not the output voltage Vc of the battery 24 detected in the first voltage detection process (step S68) is equal to or higher than the first reference voltage Vth1 (step S72). For example, the first reference voltage Vth1 is set to a voltage at which it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “A mode”.

  When the output voltage Vc is equal to or higher than the first reference voltage Vth1, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S80). In this case, if the drive request received in step S30 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S30 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the output voltage Vc is less than the first reference voltage Vth1, the CPU 40 detects the output voltage Vo of the battery 24 detected in the second voltage detection process (step S64) and the first voltage detection process (step S68). The internal resistance value calculation process for calculating the internal resistance value Rimp of the battery 24 is performed from the output voltage Vc of the battery 24 detected in (Step S74). The internal resistance value Rimp of the battery 24 can be calculated by the following equation.

式（１）において、ｒは負荷装置５４の負荷に相当する抵抗値である。

In Equation (1), r is a resistance value corresponding to the load of the load device 54.

  FIG. 11A is a graph showing the secular change of the internal resistance of the battery, and FIG. 11B is a graph showing the secular change of the battery capacity. In FIG. 11A, the horizontal axis represents the number of years elapsed, and the vertical axis represents the internal resistance of the battery. In FIG. 11B, the horizontal axis represents the number of years elapsed, and the vertical axis represents the battery capacity based on when the number of years elapsed is zero.

  According to FIG. 11A, the internal resistance of the battery monotonously increases with the elapsed years. Further, according to FIG. 11B, the battery capacity monotonously decreases with the elapsed years. Therefore, by calculating the internal resistance of the battery, it is possible to grasp the deterioration degree of the battery due to aging of the battery.

  After step S74 in the flowchart of FIG. 10, the CPU 40 determines whether or not the internal resistance value Rimp calculated in the internal resistance value calculation process (step S74) is equal to or less than the threshold value Rth1 (step S76).

  When the internal resistance value Rimp is equal to or less than the threshold value Rth1, the CPU 40 is permitted to operate the GPS device 50 in the “A mode” or the “B mode” (step S80). In this case, if the drive request received in step S60 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S60 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the internal resistance value Rimp exceeds the threshold value Rth1 in step S74, the CPU 40 determines whether or not the internal resistance value Rimp is equal to or less than the threshold value Rth2 (step S78). Note that threshold value Rth2> threshold value Rth1.

  When the internal resistance value Rimp is equal to or less than the threshold value Rth2, the CPU 40 is permitted to operate the GPS device 50 in the “B mode” or the “C mode (not operated)” (step S82). In this case, if the drive request received in step S60 is “A mode”, the CPU 40 operates the GPS device 50 in “B mode” or “C mode (not operated)”. If the drive request received in step S60 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the internal resistance value Rimp exceeds the threshold value Rth2 in step S78, the CPU 40 operates the GPS device 50 in the “C mode (do not operate)” (step S84). In this case, the CPU 40 operates the GPS device 50 in the “C mode (do not operate)” regardless of whether the drive request received in step S60 is “A mode” or “B mode”.

  As the threshold value Rth1, for example, a threshold value is set so that it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “A mode”.

  As the threshold value Rth2, for example, a threshold value is set such that it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “B mode”.

  As shown in the graphs of FIGS. 11A and 11B, there is a correlation between the internal resistance value of the battery and the deterioration of the battery capacity. Therefore, according to the third embodiment, since the operation of the GPS device 50 is controlled based on the internal resistance value Rimp of the battery 24, the state of the battery 24 including the progress of deterioration of the battery 24, the influence of the ambient temperature, etc. Appropriate control becomes possible accordingly.

  Further, it is considered that the larger the internal resistance value Rimp, the more the battery is deteriorated and the battery capacity is small. Therefore, when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage, the larger the internal resistance value Rimp, the more electricity is consumed per operation period of the reception calculation unit. By controlling the operation of the GPS device 50 so as to be small, it is possible to avoid malfunctions of the GPS wristwatch due to insufficient battery capacity.

[Modification]
In the above-described third embodiment, when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage, the larger the internal resistance value Rimp is, the one operation of the reception calculation unit In this example, the operation of the GPS device 50 is controlled so that the amount of electricity consumed per period is small, but the output voltage of the battery unit detected by the second voltage detection process is lower than the second reference voltage. Alternatively, the operation of the GPS device 50 may be controlled such that the greater the internal resistance value Rimp, the smaller the amount of electricity consumed per operation period of the reception calculation unit.

  FIG. 12 is a flowchart for explaining a modified example of the operation control of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the third embodiment. Note that the same processes as those in the third embodiment described above are denoted by the same reference numerals as those in the flowchart of FIG. 10, and detailed descriptions thereof are omitted.

  The voltage detection device 52 detects the output voltage of the battery 24 when the load device 54 is not operating from the step (step S60) in which the CPU 40 determines whether or not there is a request to drive the GPS device 50 (GPS drive request). The operation until the second voltage detection process to be acquired (step S64) is the same as that of the second embodiment.

  Next, the CPU 40 determines whether or not the output voltage Vo of the battery 24 detected in the second voltage detection process (step S64) is equal to or higher than the second reference voltage Vth2 (step S86). For example, the second reference voltage Vth2 is set to a voltage at which it can be determined that the battery capacity is sufficient even when the GPS device 50 operates in the “A mode”.

  When the output voltage Vo is equal to or higher than the second reference voltage Vth2, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S80). In this case, if the drive request received in step S60 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S60 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  When the output voltage Vo is less than the second reference voltage Vth2, the CPU 40 drives the load device 54 for a given time prior to supplying power to the GPS device 50 (step S66). Thereafter, the first voltage detection process is performed (step S68), and the operation until the driving of the load device 54 is ended (step S70) is the same as that in the third embodiment.

  After completing the driving of the load device 54 (step S70), the CPU 40 determines whether or not the internal resistance value Rimp calculated in the internal resistance value calculation process (step S74) is equal to or less than the threshold value Rth1 (step S76). Subsequent operations are the same as those in the third embodiment.

  As described above, when the output voltage of the battery unit detected by the second voltage detection process is lower than the second reference voltage, the larger the internal resistance value Rimp, the more the reception operation unit consumes per operation period. By controlling the operation of the GPS device 50 so as to reduce the amount of electricity, it is possible to avoid problems with the operation of the GPS wristwatch due to insufficient battery capacity.

2-4. Fourth Embodiment The structure and circuit configuration of the GPS wristwatch according to the fourth embodiment are the same as the structure and circuit configuration of the GPS wristwatch according to the first embodiment shown in FIGS. To do.

[Control of operation of reception calculation unit by control unit]
Hereinafter, control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the fourth embodiment will be described. In this embodiment, the operation of the reception calculation unit includes a plurality of operation modes, and an example in which the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes will be described.

  Further, in the following description, the operation mode of the reception calculation unit with the relatively large amount of electricity consumed per operation period of the reception calculation unit is “A mode”, and the power consumption per operation period of the reception calculation unit. The operation mode of the reception calculation unit with the smaller amount is “B mode”, and the operation mode of the reception calculation unit when driving power is not supplied to the reception calculation unit (when the reception calculation unit is not operated) is “C mode”. " Details of an operation example of the reception calculation unit in the “A mode” and the “B mode” will be described later. For convenience of explanation, the case where the reception arithmetic unit is not operated is expressed as “operate in“ C mode (do not operate) ””.

  FIG. 13 is a flowchart for explaining the control of the operation of the reception calculation unit (GPS device 50) by the control unit (CPU 40) in the fourth embodiment.

  The CPU 40 determines whether or not there is a request for driving the GPS device 50 (GPS drive request) (step S90). The CPU 40 may itself generate a GPS drive request at periodic timing (for example, every 24 hours). In addition, the CPU 40 may determine that a GPS driving request has been made at a timing when the input device 46 receives an operation of a specific user.

  If it is determined in step S90 that there is no GPS drive request, the CPU 40 waits for a predetermined time (step S92), and repeats step S90 and step S92 until there is a GPS drive request.

  If it is determined in step S90 that a GPS drive request has been made, the output voltage of the battery 24 when the load device 54 is not operating is detected by the voltage detection device 52, and a second voltage detection process to be acquired is performed ( Step S94).

  Note that the second voltage detection process (step S94) is replaced between step S90 and driving of the load device 54 described later (step S96), instead of driving end of the load device 54 described later (step S100) and internal resistance. You may perform between value calculation processes (step S102).

  Next, the CPU 40 drives the load device 54 for a given time prior to supplying power to the GPS device 50 (step S96). In the circuit diagram shown in FIG. 5, the load device 54 is driven by connecting the switch 53 to the load device 54 side based on the control signal 40A. The given time is a time until the output voltage of the battery 24 is stabilized to some extent, and may be, for example, about 5 seconds.

  Next, the CPU 40 detects the output voltage of the battery 24 during the operation of the load device 54 by the voltage detection device 52 and performs a first voltage detection process to be acquired (step S98). While the load device 54 is operating, the output voltage of the battery 24 is lower than when the load device 54 is not operating.

  After a given time has elapsed from step S96, the CPU 40 finishes driving the load device 54 (step S100). In the circuit diagram shown in FIG. 5, the driving of the load device 54 is terminated by disconnecting the switch 53 from the load device 54 based on the control signal 40A.

  Next, the CPU 40 calculates the battery 24 from the output voltage Vo of the battery 24 detected in the second voltage detection process (step S94) and the output voltage Vc of the battery 24 detected in the first voltage detection process (step S98). An internal resistance value calculation process for calculating the internal resistance value Rimp is performed (step S102). The internal resistance value Rimp of the battery 24 can be calculated by the above formula (1).

  Next, the CPU 40 performs estimation calculation processing for estimating the output voltage of the battery 24 during the operation of the GPS device 50 from the internal resistance value Rimp and the load applied to the battery 24 during the operation of the GPS device 50 (step S104). .

  The output voltage Vca of the battery 24 during operation of the GPS device 50 when the load (for example, 100Ω) on the battery 24 when the GPS device 50 operates in the “A mode” is Ra can be estimated by the following equation.

同様に、ＧＰＳ装置５０が「Ｂモード」で動作した場合の電池２４に対する負荷（例えば２００Ω）をＲｂとしたときのＧＰＳ装置５０の動作時における電池２４の出力電圧Ｖｃｂは、以下の式で推測できる。

Similarly, the output voltage Vcb of the battery 24 during operation of the GPS device 50 when the load (for example, 200Ω) on the battery 24 when the GPS device 50 operates in the “B mode” is Rb is estimated by the following equation: it can.

なお、「Ａモード」は「Ｂモード」よりも負荷が大きいので、Ｒａ＜Ｒｂの関係が成立する。したがって、式（２）及び式（３）より、Ｖｃａ＜Ｖｃｂの関係が成立する。

Since “A mode” has a larger load than “B mode”, the relationship of Ra <Rb is established. Therefore, the relationship of Vca <Vcb is established from the equations (2) and (3).

  Next, the CPU 40 determines whether or not the output voltage Vca calculated in the estimation calculation process (step S104) is equal to or higher than the threshold voltage Vth (step S106).

  When the output voltage Vca is equal to or higher than the threshold voltage Vth, the CPU 40 is permitted to operate the GPS device 50 in “A mode” or “B mode” (step S110). In this case, if the drive request received in step S90 is “A mode”, the CPU 40 operates the GPS device 50 in “A mode”. If the drive request received in step S90 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  In step S106, when the output voltage Vca is less than the threshold voltage Vth, the CPU 40 determines whether or not the output voltage Vcb is equal to or higher than the threshold voltage Vth (step S108).

  When the output voltage Vcb is equal to or higher than the threshold voltage Vth, the CPU 40 is permitted to operate the GPS device 50 in the “B mode” or the “C mode (do not operate)” (step S112). In this case, if the drive request received in step S90 is “A mode”, the CPU 40 operates the GPS device 50 in “B mode” or “C mode (not operated)”. If the drive request received in step S90 is “B mode”, the CPU 40 operates the GPS device 50 in “B mode”.

  In step S108, when the output voltage Vcb is less than the threshold voltage Vth, the CPU 40 operates the GPS device 50 in the “C mode (do not operate)” (step S114). In this case, regardless of whether the drive request received in step S90 is “A mode” or “B mode”, the CPU 40 causes the GPS device 50 to operate in “C mode (do not operate)”.

  As the threshold voltage Vth, for example, a threshold voltage that can be determined to have sufficient battery capacity even when the GPS device 50 operates is set.

  According to the fourth embodiment, the output voltage of the battery 24 during the operation of the GPS device 50 is estimated, and the operation of the GPS device 50 is controlled based on the estimated value. Appropriate control becomes possible according to the state of the battery unit including the influence and the like.

  Further, it is considered that the smaller the output voltage of the battery 24 during the operation of the GPS device 50 estimated by the estimation calculation process, the smaller the remaining battery capacity. Therefore, by controlling the operation of the GPS device so that the smaller the output voltage of the battery 24 during the operation of the GPS device estimated by the estimation calculation process, the smaller the amount of electricity consumed per operation period of the reception calculation unit, It is possible to avoid malfunctions due to insufficient battery capacity.

3. Example of operation mode of GPS wristwatch (GPS device) In the above description, the operation mode of the reception calculation unit with the relatively large amount of electricity consumed per operation period of the reception calculation unit is “A mode”, When the operation mode of the reception calculation unit having a relatively small amount of electricity consumed per operation period of the calculation unit is “B mode” and driving power is not supplied to the reception calculation unit (when the reception calculation unit is not operated) The operation mode of the reception calculation unit has been described as “C mode”. Hereinafter, details of an operation example of the reception calculation unit in the “A mode” and “B mode” will be described.

3-1. Time information acquisition mode and position information acquisition mode The operation of the GPS device (reception calculation unit) 50 includes a time information acquisition mode for generating time information based on satellite information and a position information for generating position information based on satellite information. Acquisition mode. In this case, the processing time is relatively short (for example, about 15 seconds to 1 minute), the time information acquisition mode with a small amount of electricity consumed per operation period is set to “B mode”, and the processing time is relatively long (for example, 30 The position information acquisition mode that consumes a large amount of electricity per operation period corresponds to the “A mode”.

[Time information acquisition mode]
FIG. 14 is a flowchart showing an example of the operation in the time information acquisition mode of the GPS wristwatch.

  When the GPS wristwatch 1 is set to the time information acquisition mode, the GPS wristwatch 1 executes time correction processing (time information acquisition mode) shown in FIG.

  When the time correction process (time information acquisition mode) is started, the GPS wristwatch 1 first controls the GPS device 50 by the CPU 40 to perform a reception process. That is, the CPU 40 activates the GPS device 50, and the GPS device 50 starts receiving a satellite signal transmitted from the GPS satellite 10 (step S210).

When reception is started, the GPS device 50 sets a search time limit T _s (step S212). Here, the search time limit T _s is a time limit from when the GPS device 50 starts the reception operation to when the satellite search process described later ends. For example, 6 seconds is set as the search time limit T _s . The search time limit T _s may be set before starting reception.

  Next, the GPS device 50 starts a satellite search process (satellite search process) (step S214). In the satellite search step, the GPS device 50 performs a process of searching for a GPS satellite 10 that can be captured.

  Specifically, for example, when there are 30 GPS satellites 10, the GPS device 50 first changes the satellite number SV from 1 to 30 while changing the satellite number SV in the same pattern as the C / A code of the satellite number SV. Generate code. Next, the GPS device 50 calculates a correlation value between the C / A code and the local code included in the baseband signal. If the C / A code and the local code included in the baseband signal are the same code, the correlation value has a peak at a predetermined timing, but if the code is different, the correlation value does not have a peak and is always almost zero.

  The GPS device 50 adjusts the local code generation timing so that the correlation value between the C / A code and the local code included in the baseband signal is maximized. If the correlation value is equal to or greater than a predetermined threshold, the satellite number SV It is determined that the GPS satellite 10 has been captured. Then, the GPS device 50 stores the captured information (for example, satellite number) of each GPS satellite 10 in a storage unit such as an SRAM included in the GPS device 50.

Next, the GPS device 50 determines whether or not the satellite search process has ended before the search time limit T _s has elapsed (steps S216 and S218). For example, when searching for the GPS satellite 10 while changing the satellite number SV from 1 to 30, the baseband unit determines whether or not the search for the GPS satellite 10 having the satellite number SV of 30 is completed. Thus, it is determined whether or not the satellite search process is completed.

If the search time limit T _s elapses before the GPS device 50 ends the satellite search process (YES in step S216), the reception operation of the GPS device 50 is forcibly ended (step S244). When the GPS wristwatch 1 is in an environment where reception is not possible, for example, when the GPS wristwatch 1 is indoors, it is very unlikely that the GPS satellite 10 can be captured even if all GPS satellites 10 are searched. If the GPS wristwatch 1 cannot detect the GPS satellite 10 that can be captured even after the search time limit T _s has elapsed, the GPS wristwatch 1 is forcibly terminated to reduce unnecessary power consumption. can do.

On the other hand, if the satellite search process is completed before the search time limit T _s has elapsed (YES in step S218), the GPS device 50 determines whether or not the GPS satellite 10 has been captured (step). S220).

  If the GPS satellite 10 cannot be captured (NO in step S220), the GPS device 50 starts the satellite search process again (step S214).

  On the other hand, when the GPS satellite 10 can be captured (YES in step S220), the GPS device 50 acquires the reception level of the satellite signal transmitted from each captured GPS satellite 10 (step S222). Specifically, the GPS device 50 calculates the power of a signal obtained by mixing a local code and a baseband signal having the same pattern as the C / A code of each captured GPS satellite 10, and obtains a reception level. The GPS device 50 stores the reception level of the satellite signal transmitted from each captured GPS satellite 10 in a storage unit such as an SRAM included in the GPS device 50.

Next, the GPS device 50 sets the satellite signal decoding time _Td (step S224). The satellite signal decoding time _Td is a time limit for the GPS device 50 to generate time correction information. The satellite signal decoding time _Td corresponds to the calculation time limit in the present invention.

  Next, the GPS device 50 starts acquiring satellite information (particularly GPS time information) of the captured GPS satellite 10 (step S226). Specifically, the GPS device performs processing for acquiring Z count data by demodulating the navigation message from each captured GPS satellite. Then, the GPS device 50 stores the acquired GPS time information in an SRAM or the like that the GPS device 50 has.

If the satellite signal decoding time _Td has elapsed before the GPS device 50 acquires satellite information of one or more GPS satellites 10 (YES in step S228), the reception operation of the GPS device 70 is forcibly terminated. (Step S244). For example, since the reception level of the satellite signal from the GPS satellite 10 is low, it is conceivable that the satellite signal decoding time _Td elapses without correctly demodulating the satellite information of one or more GPS satellites 10.

On the other hand, when the satellite information of one or more GPS satellites 10 can be acquired before the satellite signal decoding time _Td elapses (YES in step S230), the GPS device 50 captures the captured GPS satellite 10 Then, one or more GPS satellites 10 are selected to start time calculation (step S232).

  Specifically, the GPS device 50 reads the satellite information (GPS time information) of the selected GPS satellite 10 from an SRAM or the like included in the GPS device 50, performs time measurement calculation, and generates time correction information. As described above, the GPS time information represents the time when the GPS satellite 10 transmits the first bit of the subframe of the navigation message. Therefore, the GPS device 50 can calculate, for example, the time difference between the internal time information and the GPS time information when the first bit of the subframe is received as time correction information necessary for correcting the internal time information. The GPS device 50 can also generate more accurate time correction information based on the GPS time information of the plurality of GPS satellites 10. And if the GPS apparatus 50 can produce | generate time correction information, time measurement calculation will be complete | finished.

If the satellite signal decoding time _Td elapses before the GPS device 50 finishes time measurement calculation (YES in step S234), the reception operation of the GPS device 70 is forcibly ended (step S244).

On the other hand, when the time measurement calculation can be completed before the satellite signal decoding time _Td elapses (YES in step S236), the CPU 40 stores the time correction information in the time measuring device 56. The internal time information is corrected (step S238).

  Then, the receiving operation of the GPS device 50 ends (step S240).

  Finally, the CPU 40 controls the display device 48 based on the corrected internal time information, and the time display is corrected (step S242).

  When the reception operation of the GPS device 50 is forcibly terminated (step S244), the CPU 40 controls the display device 48 and displays a reception failure (step S246).

[Location information acquisition mode]
FIG. 15 is a flowchart showing an example of the operation in the position information acquisition mode of the GPS wristwatch. In the following description, the description of the same processing as in the time information acquisition mode is omitted or simplified.

  When the GPS wristwatch 1 is set to the position information acquisition mode, the time difference correction process (position information acquisition mode) shown in FIG. 15 is executed.

  When the time difference correction process (position information acquisition mode) is started, the GPS wristwatch 1 first controls the GPS device 50 by the CPU 40 to perform a reception process. That is, the CPU 40 activates the GPS device 50, and the GPS device 50 starts receiving a satellite signal transmitted from the GPS satellite 10 (step S250).

When reception is started, the GPS device 50 sets a search time limit T _s (step S252).

  Next, the GPS device 50 starts a satellite search process (satellite search process) (step S254).

Next, the GPS device 50 determines whether or not the satellite search process has ended before the search time limit T _s has elapsed (steps S256 and S258).

If the search time limit T _s has elapsed before the GPS device 50 ends the satellite search process (YES in step S256), the reception operation of the GPS device 50 is forcibly ended (step S284).

On the other hand, if the satellite search process is completed before the search time limit T _s has elapsed (YES in step S258), the GPS device 50 can capture a predetermined number (N) or more of the GPS satellites 10. It is determined whether or not (step S260). Here, in order to specify the three-dimensional position (x, y, z) of the GPS wristwatch 1, x, y, z are three unknowns. Therefore, in order to calculate the three-dimensional position (x, y, z) of the GPS wristwatch 1, GPS time information and orbit information of three or more GPS satellites 10 are required. Furthermore, in order to improve positioning accuracy, if the time error between the internal time information of the GPS wristwatch 1 and the GPS time information is also an unknown number, GPS time information and orbit information of four or more GPS satellites 10 are necessary.

  If N (for example, four) or more GPS satellites 10 cannot be captured (NO in step S260), the GPS device 50 starts the satellite search process again (step S254).

  On the other hand, when N (for example, four) or more GPS satellites 10 can be captured (YES in step S260), the GPS device 50 receives the satellite signals transmitted from the captured GPS satellites 10. A level is acquired (step S262). The GPS device 50 stores the reception level of the satellite signal transmitted from each captured GPS satellite 10 in a storage unit such as an SRAM included in the GPS device 50.

Next, the GPS device 50 sets the satellite signal decoding time _Td (step S264). The satellite signal decoding time _Td is a time limit for the GPS device 50 to generate time correction information. The satellite signal decoding time _Td corresponds to the calculation time limit in the present invention.

  Next, the GPS device 50 starts acquiring satellite information (particularly GPS time information and orbit information) of the captured GPS satellite 10 (step S266). Specifically, the GPS device 50 performs a process of demodulating each captured navigation message from each GPS satellite and obtaining Z count data and ephemeris parameters. The GPS device 50 stores the acquired GPS time information and orbit information in an SRAM or the like included in the GPS device 50.

If the satellite signal decoding time _Td has elapsed before the GPS device 50 acquires satellite information of N (for example, four) or more GPS satellites 10 (YES in step S268), the reception operation of the GPS device 50 is performed. The process is forcibly terminated (step S284). For example, since the reception level of the satellite signal from the GPS satellite 10 is low, the satellite signal decoding time _Td elapses without correctly demodulating satellite information of N (for example, four) or more GPS satellites 10. Can be considered.

On the other hand, when the satellite information of N (for example, four) or more GPS satellites 10 can be acquired before the satellite signal decoding time _Td elapses (YES in step S270), the GPS device 50 A combination of N (for example, four) GPS satellites 10 is selected from the captured GPS satellites 10 and positioning calculation (corresponding to the positioning calculation process in the present invention) is started (step S272).

  Specifically, the GPS device 50 reads the satellite information (GPS time information and orbit information) of the selected N (for example, four) GPS satellites 10 from the SRAM or the like included in the GPS device 50 and performs positioning calculation. , Position information (latitude and longitude (coordinate values) of the place where the GPS wristwatch 1 is located) is generated. As described above, the GPS time information represents the time when the GPS satellite 10 transmits the first bit of the subframe of the navigation message. Therefore, the GPS device 50 determines the number of GPS satellites 10 and the GPS wristwatch 1 based on the difference between the internal time information and the GPS time information when the first bit of the subframe is received and the time correction data. Can be calculated respectively. The GPS device 50 can calculate the positions of N (for example, four) GPS satellites 10 based on the orbit information. Then, the GPS device 50 determines the GPS wristwatch 1 based on the pseudo distance between the N (for example, four) GPS satellites 10 and the GPS wristwatch 1 and the positions of the N (for example, four) GPS satellites 10. Position information can be generated.

  In addition, the GPS device 50 calculates a positioning error (the location where the GPS wristwatch 1 is actually located and the maximum distance between the locations specified by the location information). For example, the GPS device 50 calculates, as a positioning error, a value obtained by multiplying a ranging error (a measurement error of a distance between the GPS satellite 10 and the GPS receiver 10) by a DOP value. As the DOP value, a PDOP value, an HDOP value, or the like can be used. And the GPS apparatus 50 continues positioning calculation until it becomes below a predetermined DOP value, and produces | generates positional information.

  The GPS device 50 refers to the time difference information stored in the flash memory or the like of the GPS device 50, and the time difference associated with the coordinate values (for example, latitude and longitude) of the GPS wristwatch 1 specified by the position information. Get the data.

  Thus, if the GPS device 50 can generate GPS time information and time difference data as time correction information, the positioning calculation ends.

If the satellite signal decoding time _Td has elapsed before the GPS device 50 finishes positioning calculation (YES in step S274), the reception operation of the GPS device 50 is forcibly terminated (step S284). For example, it is conceivable that the satellite signal decoding time _Td elapses without specifying the time difference data associated with the coordinate values (for example, latitude and longitude) of the GPS wristwatch 1 as one.

On the other hand, if the positioning calculation can be completed before the satellite signal decoding time _Td elapses (YES in step S276), the CPU 40 uses the time correction information to store the internal time stored in the time measuring device 56. The time information is corrected (step S278).

  Then, the receiving operation of the GPS device 50 ends (step S280).

  Finally, the CPU 40 controls the display device 48 based on the corrected internal time information, and the time display (time difference) is corrected (step S282).

  If the reception operation of the GPS device 50 is forcibly terminated (step S284), the CPU 40 controls the display device 48 and displays a reception failure (step S286).

3-2. Long-time search mode and short-time search mode The operation of the GPS device (reception calculation unit) 50 includes a search limit that is a time limit from when the GPS device 50 starts a reception operation until a satellite search process described later ends. A long-time search mode in which the time T _s is relatively long and a short-time search mode in which the time T _s is relatively short may be included. In this case, the long-time search mode in which the processing time is relatively long and the amount of electricity consumed per operation period is large is referred to as “A mode”, and the processing time is relatively short and the amount of electricity consumed per operation period is small. The search mode corresponds to “B mode”.

In the flowchart of FIG. 14 (time information acquisition mode), the short by at step S212, the prolonged search mode by setting the search time limit T _s a long time, set in a short time the search limit time T _s The time search mode can be set.

Likewise, in the flowchart (positioning information acquisition mode) in FIG. 15, in step S252, the long-time search mode by setting the search time limit T _s a long time, set in a short time the search limit time T _s Thus, the short search mode can be set.

3-2. Long-time decoding mode and short-time decoding mode In the operation of the GPS device (reception calculation unit) 50, the GPS device 50 uses a satellite signal decoding time _Td that is a time limit for the GPS device 50 to generate time correction information. May include a long-time decoding mode for a long time (for example, about 3 minutes) and a short-time decoding mode for a relatively short time (for example, about 1 minute). In this case, the long-time decoding mode in which the processing time is relatively long and the amount of electricity consumed per operation period is large is “A mode”, and the processing time is relatively short and the amount of electricity consumed per operation period is small. The decode mode corresponds to “B mode”.

In the flowchart of FIG. 14 (time information acquisition mode), in step S224, the satellite signal decoding time _Td is set to a long time by setting the satellite signal decoding time _Td to a long time, and the satellite signal decoding time _Td is set to a short time. The short-time decoding mode can be set.

Likewise, in the flowchart (positioning information acquisition mode) in FIG. 15, in step S262, the long-time decoding mode by setting the satellite signal decoding time T _d to a long time, in a short time the satellite signal decoding time T _d By setting, it is possible to set to the short-time decoding mode.

3-3. High-accuracy mode and low-accuracy mode For the operation of the GPS device (reception calculation unit) 50, the GPS device 50 sets the DOP value at which the GPS device 50 finishes the positioning calculation to be relatively small (highly accurate). A mode and a low-accuracy mode that is set relatively large (with low accuracy) may be included. In this case, the high-accuracy mode in which the processing time is relatively long and the amount of electricity consumed per operation period is large is referred to as “A mode”, and the low-accuracy mode in which the processing time is relatively short and the amount of electricity consumption per operation period is small. Corresponds to “B mode”.

  In the flowchart of FIG. 15 (positional information acquisition mode), when performing the positioning calculation in step S272, the DOP value for ending the positioning calculation is set to a high accuracy mode by setting the DOP value for ending the positioning calculation to a small value. By doing so, the low accuracy mode can be set.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

  In the above embodiment, the operation of the reception calculation unit includes a plurality of operation modes, and the control unit controls the operation of the reception calculation unit by selecting one of the plurality of operation modes. For example, it is possible to control the operation of the reception calculation unit by continuously changing various set values such as the DOP value and the search time limit.

  In the above-described embodiment, the case where the number of operation modes is three has been described. However, the number of operation modes is not limited to three, and may be two or four or more.

  Further, among the above-described examples of the operation modes, it is possible to combine the operation modes of different concepts (for example, the position information acquisition mode and the long-time search mode) into one operation mode.

  In each of the above-described embodiments, the GPS satellite has been described as the position information satellite. However, the present invention is not limited to the GPS satellite, but other global navigation satellite systems (GNSS) such as Galileo and GLONASS, and stationary satellites such as SBAS. Position information satellites that transmit satellite signals including position information and time information such as quasi-zenith satellites may also be used.

The figure for demonstrating the outline | summary of a GPS system. FIG. 2A to FIG. 2C are diagrams for explaining a configuration of a navigation message. FIGS. 3A and 3B are views for explaining the structure of the GPS wristwatch according to the first embodiment. The figure for demonstrating the circuit structure of the wristwatch with GPS of 1st Embodiment. The figure for demonstrating the circuit structural example of a load apparatus. The flowchart for demonstrating control of the operation | movement of the reception calculating part by the control part in 1st Embodiment. The graph showing the change of the output voltage of a battery part at the time of load part operation | movement and reception calculating part operation | movement. The flowchart for demonstrating control of the operation | movement of the reception calculating part by the control part in 2nd Embodiment. The flowchart for demonstrating the modification of operation | movement control of the reception calculating part by the control part in 2nd Embodiment. The flowchart for demonstrating control of the operation | movement of the reception calculating part by the control part in 3rd Embodiment. FIG. 11A is a graph showing the secular change of the internal resistance of the battery, and FIG. 11B is a graph showing the secular change of the battery capacity. The flowchart for demonstrating the modification of control of the operation | movement of the reception calculating part by the control part in 3rd Embodiment. The flowchart for demonstrating control of the operation | movement of the reception calculating part by the control part in 4th Embodiment. The flowchart which shows an example of the operation | movement in the time information acquisition mode of a wristwatch with GPS. The flowchart which shows an example of the operation | movement in the positional information acquisition mode of a wristwatch with GPS.

Explanation of symbols

1 GPS receiver (GPS wristwatch), 10 GPS satellite, 11 dial, 12 pointer, 13 display, 14 crown, 15 button, 16 button, 17 outer case, 18 bezel, 19 surface glass, 20 motor coil, 21 magnetic Sheet, 22 Charging coil, 23 Back glass, 24 Battery, 25 Circuit board, 26 Back cover, 27 GPS antenna, 28 Charge control circuit, 29 Regulator, 30 Receiving IC (receiving circuit), 32 Bus, 40 Control IC (CPU; control unit), 42 RAM, 44 ROM, 46 input device, 48 display device, 50 GPS device, 52 voltage detection device, 53 switch, 54 load device

Claims (17)

An electronic device having a function of receiving a satellite signal transmitted from a position information satellite,
A battery section;
A receiving operation unit that is driven by power supply from the battery unit, receives the satellite signal, and performs arithmetic processing to acquire satellite information from the received satellite signal;
A voltage detection unit for detecting an output voltage of the battery unit;
A load unit that applies a lighter load to the battery unit than the reception calculation unit;
A control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit,
The controller is
Prior to power supply from the battery unit to the reception calculation unit, the load unit is operated, and a first voltage detection process is performed in which the voltage detection unit detects an output voltage of the battery unit during operation of the load unit. Done
An electronic apparatus that controls an operation of the reception calculation unit after an operation of the load unit based on an output voltage of the battery unit detected in the first voltage detection process. The electronic device according to claim 1,
The control unit operates the reception calculation unit such that the lower the output voltage of the battery unit detected in the first voltage detection process, the smaller the amount of electricity consumed per operation period of the reception calculation unit. An electronic device characterized by controlling The electronic device according to claim 1,
The controller is
Performing a second voltage detection process of detecting the output voltage of the battery unit during non-operation of the load unit by the voltage detection unit;
The operation of the reception calculation unit after the operation of the load unit is controlled based on the output voltage of the battery unit detected by the first voltage detection process and the second voltage detection process. Electronic equipment. The electronic device according to claim 3,
The control unit detects the output voltage of the battery unit detected by the second voltage detection process when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage. Is lower than the second reference voltage, the larger the difference between the output voltages of the battery units detected in the first voltage detection process and the second voltage detection process, the greater the An electronic apparatus characterized in that the operation of the reception calculation unit is controlled so that the amount of electricity consumed per operation period is small. The electronic device according to claim 3,
The controller is
Performing an internal resistance value calculation process for calculating an internal resistance value of the battery unit from an output voltage of the battery unit detected by the first voltage detection process and the second voltage detection process;
An electronic apparatus that controls the operation of the reception calculation unit after the operation of the load unit based on the internal resistance value. The electronic device according to claim 5,
The control unit detects the output voltage of the battery unit detected by the second voltage detection process when the output voltage of the battery unit detected by the first voltage detection process is lower than the first reference voltage. Is lower than the second reference voltage, the operation of the reception calculation unit is controlled such that the larger the internal resistance value, the smaller the amount of electricity consumed per operation period of the reception calculation unit. Features electronic equipment. The electronic device according to claim 5,
The controller is
From the internal resistance value and the load on the battery unit during operation of the reception calculation unit, performing an estimation calculation process for estimating the output voltage of the battery unit during operation of the reception calculation unit,
An electronic apparatus that controls an operation of the reception calculation unit after an operation of the load unit based on an output voltage of the battery unit during an operation of the reception calculation unit estimated by the estimation calculation process. The electronic device according to claim 7,
The control unit is configured to reduce the amount of electricity consumed per operation period of the reception calculation unit as the output voltage of the battery unit during operation of the reception calculation unit estimated by the estimation calculation process decreases. An electronic device that controls an operation of a calculation unit. The electronic device according to any one of claims 1 to 8,
The operation of the reception calculation unit includes a plurality of operation modes,
The said control part controls the operation | movement of the said reception calculating part by selecting either of these operation modes, The electronic device characterized by the above-mentioned. The electronic device according to claim 9,
The operation of the reception calculation unit includes a position information acquisition mode for generating position information based on the satellite information, and a time information acquisition mode for generating time information based on the satellite information,
The said control part controls the operation | movement of the said reception calculating part by selecting from the said position information acquisition mode and the said time information acquisition mode, The electronic device characterized by the above-mentioned. The electronic device according to claim 10,
The reception calculation unit performs a positioning calculation process for generating position information by performing a positioning calculation based on the satellite information until it becomes a given DOP value or less in the position information acquisition mode,
The said control part controls the operation | movement of the said reception calculating part by changing the said given DOP value, The electronic device characterized by the above-mentioned. The electronic device according to any one of claims 1 to 11,
The reception calculation unit performs a satellite search process for searching for the position information satellite within a given search time limit based on the satellite signal,
The said control part controls the operation | movement of the said reception calculating part by changing the said given search time limit, The electronic device characterized by the above-mentioned. The electronic device according to claim 1,
The control unit controls the operation of the reception calculation unit by changing a calculation time limit for performing calculation processing for acquiring satellite information from the satellite signal received by the reception calculation unit. . The electronic device according to any one of claims 1 to 13,
The said control part controls the operation | movement of the said reception calculating part by selecting whether the said reception calculating part is operated after the operation | movement of the said load part, The electronic device characterized by the above-mentioned. The electronic device according to any one of claims 1 to 14,
Including a timekeeping section that holds internal time information,
The said control part corrects the said internal time information based on the said satellite information which the said reception calculating part acquired, The electronic device characterized by the above-mentioned. An electronic device having a function of receiving a satellite signal transmitted from a position information satellite,
A battery section;
A receiving operation unit that is driven by power supply from the battery unit, receives the satellite signal, and performs arithmetic processing to acquire satellite information from the received satellite signal;
A voltage detection unit for detecting an output voltage of the battery unit;
A load unit that applies a lighter load to the battery unit than the reception calculation unit;
A control method of an electronic device including a control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit,
The control unit is
Operating the load unit prior to supplying power from the battery unit to the reception operation unit;
Performing a first voltage detection process for detecting, by the voltage detection unit, an output voltage of the battery unit during operation of the load unit;
Controlling the operation of the reception calculation unit after the operation of the load unit based on the output voltage of the battery unit detected in the first voltage detection process. Control method. An electronic device having a function of receiving a satellite signal transmitted from a position information satellite,
A battery section;
A receiving operation unit that is driven by power supply from the battery unit, receives the satellite signal, and performs arithmetic processing to acquire satellite information from the received satellite signal;
A voltage detection unit for detecting an output voltage of the battery unit;
A load unit that applies a lighter load to the battery unit than the reception calculation unit;
A control method of an electronic device including a control unit that controls operations of the reception calculation unit, the voltage detection unit, and the load unit,
The control unit is
Operating the load unit prior to supplying power from the battery unit to the reception calculation unit;
First voltage detection processing for detecting the output voltage of the battery unit during operation of the load unit by the voltage detection unit, and detection of the output voltage of the battery unit during non-operation of the load unit by the voltage detection unit Performing a second voltage detection process,
Controlling the operation of the reception calculation unit after the operation of the load unit based on the output voltage of the battery unit detected by the first voltage detection process and the second voltage detection process. A method for controlling an electronic device, comprising:

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