JP2010066151A - Wrist device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wrist device capable of improving decorativeness and mountability by enabling radio reception through solar cells and thus reducing limitation in antenna arrangement. <P>SOLUTION: A GPS (global positioning system) wrist watch 3 comprises a solar cell 22 for photovoltaic power generation, a secondary cell 24, and a GPS antenna 27. The secondary cell 24 accumulates the charge generated by the photovoltaic power generation of the solar cell 22. The GPS antenna 27 receives radio waves passing through the solar cell 22. The GPS wrist watch 3 further comprises a charge control circuit 28 and a controller (CPU ( central processing unit)) 40. The charge control circuit 28 and the controller 40 control to electrically connect or disconnect between an electrode of the solar cell 22 and an electrode of the secondary cell 24 during receiving radio waves. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wrist device having a function of receiving a predetermined radio wave using power generated by photovoltaic power generation as a power source.

In recent years, various wrist devices that receive radio waves and acquire information superimposed on the radio waves have been developed. For example, an artificial satellite (GPS satellite) orbiting an orbit over the earth transmits a radio wave superimposed with time information and orbit information, and a ground receiver (GPS receiver) receives this radio wave and determines its position. A wristwatch that acquires the current position, date, accurate time, and the like using a GPS (Global Positioning System) system for positioning has been developed. For example, wristwatches described in Patent Document 1 and Patent Document 2 have been proposed.
JP 2000-138607 A Japanese Patent No. 4404898

  In the wristwatch described in Patent Document 1 or Patent Document 2, the location where the antenna is stored is a protrusion that can be visually recognized from the outside. There is. Therefore, in these watches, for example, it is conceivable that the dial is made of a member that transmits radio waves and the antenna is arranged inside the watch on the back side of the dial to improve the decoration and wearability.

  On the other hand, recently, wrist devices that receive radio waves using power generated by photovoltaic power generation of solar cells as a power source have been developed. Generally, a solar cell is designed so that the area on which light is incident is as large as possible in order to increase the power generation efficiency. Therefore, for example, in a wristwatch equipped with a solar cell, the solar cell is arranged so that the surface of the solar cell faces almost the entire back surface of the dial in consideration of decorativeness and the like. As a result, when an antenna is arranged inside the wristwatch on the back side of the solar cell for the purpose of improving the decoration, the antenna receives radio waves that have passed through the solar cell. However, since the solar cell is a conductor, it has the effect of shielding radio waves and degrades the reception situation. In particular, solar cells exhibit a stronger shielding effect against microwaves such as radio waves transmitted from GPS satellites. Therefore, if a wristwatch that receives microwaves is equipped with a solar cell, in order to improve the power generation efficiency of the solar cell while maintaining reliable reception, restrictions on the antenna arrangement become large, and decoration and wearability are improved. It was difficult.

  The present invention has been made in view of the above-described problems, and relaxes restrictions on antenna arrangement by enabling reception of radio waves that have passed through a solar cell, thereby improving decorativeness and wearability. An object of the present invention is to provide a wrist device that can be used.

  (1) The present invention is a wrist device having a function of receiving a predetermined radio wave using power generated by photovoltaic power as a motive power source, and a solar cell that performs the photovoltaic power generation, and the photovoltaic power generation of the solar cell. A secondary battery that accumulates the generated electric charge, an antenna that receives the radio wave that has passed through the solar cell, and an electrical connection between the electrode of the solar cell and the electrode of the secondary battery when receiving the radio wave Or a connection control unit for controlling disconnection.

  The secondary battery may be a power storage unit that can store electric charge, and may be, for example, a capacitor.

  For example, the connection control unit is connected between the electrode of the solar cell and the electrode of the secondary battery, and opens and closes based on an open / close control signal, an open / close control unit that generates the open / close control signal, May be included.

  In the wrist device of the present invention, electrical connection or disconnection control is performed between the electrode of the solar cell and the electrode of the secondary battery. Therefore, even if the antenna is arranged inside the wrist device on the back side of the solar cell, by electrically connecting or disconnecting between the electrode of the solar cell and the electrode of the secondary battery according to a given condition, Reliable reception can be maintained. Therefore, according to the present invention, restrictions on the antenna arrangement can be relaxed, so that it is possible to provide a wrist device that can improve decoration and wearability.

  Further, according to the present invention, since the antenna can be arranged inside the wrist device on the back side of the solar cell, the restriction on the antenna arrangement can be relaxed, and a wrist device that can be easily used by the user can be provided.

  (2) In the wrist device of the present invention, the connection control unit electrically disconnects the electrode of the solar cell and the electrode of the secondary battery from the start to the end of reception of the radio wave. You may make it control so that it may do.

  According to the present invention, when the solar cell electrode and the secondary battery electrode are electrically connected, the solar cell electrode exhibits a high shielding effect. Until the process is completed, the solar cell electrode and the secondary battery electrode are electrically disconnected to reduce the shielding effect of the solar cell electrode, so that radio waves are not blocked by the solar cell as much as possible. Reliable reception can be ensured by passing the solar cell.

  (3) The wrist device of the present invention includes a reception level detection unit that detects the reception level of the radio wave, and the connection control unit performs the control based on the detection result of the reception level at the start of reception of the radio wave. You may make it perform.

  According to the present invention, since the connection between the electrode of the solar cell and the electrode of the secondary battery is controlled according to the reception level at the start of radio wave reception, depending on the situation at the start of radio wave reception. The power generation efficiency of the solar cell can be optimized while maintaining reliable reception.

  (4) In the wrist device of the present invention, the connection control unit may perform the control based on the detection result of the reception level at a predetermined timing even during reception of the radio wave.

  For example, when reception starts indoors but moves outdoors during reception, radio waves sent from GPS satellites are no longer obstructed by the roof, so the reception level of radio waves is easier to receive. To change. According to the present invention, the electrical connection or disconnection between the electrode of the solar cell and the electrode of the secondary battery can be more precisely controlled during reception according to the detection result of the radio wave reception level. Therefore, it is possible to optimize the power generation efficiency of the solar cell while maintaining reliable reception.

  (5) In the wrist device of the present invention, the connection control unit electrically disconnects between the electrode of the solar cell and the electrode of the secondary battery when the detected reception level is lower than a predetermined value. You may control to do.

  According to the present invention, when the radio wave reception status is poor, the solar cell electrode and the secondary battery electrode are electrically disconnected, so that reliable reception is maintained according to the radio wave reception status. Can do.

  (6) The wrist device of the present invention includes an illuminance detection unit that detects illuminance of light incident on the solar cell, and the connection control unit is configured to detect the illuminance based on the detection result of the illuminance at the start of reception of the radio wave. Control may be performed.

  For example, a solar cell acts as an optical sensor in which the illuminance of light incident on the solar cell and the output current change proportionally. Illuminance can be detected by using the solar cell as the illuminance detection unit.

  The connection control unit may compare the detection result of the illuminance with a certain threshold value and electrically connect or disconnect between the solar cell electrode and the secondary battery electrode. In addition, the connection control unit changes the threshold value in consideration of the surrounding environment during the reception operation, compares the detection result of the illuminance with the threshold value, and electrically connects the electrode of the solar cell and the electrode of the secondary battery. You may make it perform control to cut | disconnect. For example, table data such as a threshold value under the sun, a threshold value when the fluorescent lamp is lit in the room, and a threshold value at night may be stored, and the threshold value may be changed according to the surrounding environment during the reception operation.

  Generally, the higher the illuminance of light incident on the solar cell, the higher the output current of the solar cell. And the electrical conductivity (photoconductivity) when the solar cell is performing photovoltaic power generation is so large that it cannot be compared with the electrical conductivity (dark conductivity) when no photovoltaic power generation is performed. In general, it can be said that the higher the electrical conductivity, the higher the effect of shielding radio waves, and the higher the illuminance of light incident on the solar cell, the worse the radio wave reception status. According to the present invention, according to the illuminance of light incident on the solar cell at the start of radio wave reception, electrical connection or disconnection control is performed between the electrode of the solar cell and the electrode of the secondary battery during the reception operation. The power generation efficiency of the solar cell can be optimized while maintaining reliable reception.

  (7) In the wrist device of the present invention, the connection control unit may perform the control based on the detection result of the illuminance at a predetermined timing even during reception of the radio wave.

  For example, when the reception starts indoors, but moves outside during reception, the illuminance of light incident on the solar cell changes. According to the present invention, the electrical connection or disconnection operation between the electrode of the solar cell and the electrode of the secondary battery is more precisely controlled according to the detection result of the illuminance of light incident on the solar cell even during reception. Can do. Therefore, it is possible to optimize the power generation efficiency of the solar cell while maintaining reliable reception.

  (8) In the wrist device of the present invention, the connection control unit electrically disconnects the electrode of the solar cell and the electrode of the secondary battery when the detected illuminance is higher than a predetermined value. You may control as follows.

  In the wrist device of the present invention, when the illuminance of light incident on the solar cell is higher than a predetermined value, the electrode of the solar cell and the electrode of the secondary battery are electrically disconnected. Therefore, according to the present invention, when the solar cell exhibits a high shielding effect by performing photovoltaic power generation, it is possible to maintain reliable reception by preventing the solar cell from performing photovoltaic power generation. it can.

  (9) In the wrist device of the present invention, the frequency of the radio wave may be limited to a microwave.

  The microwave is generally a radio wave having a wavelength of 100 μm to 1 m and a frequency of 300 MHz to 3 THz, and includes decimeter wave (UHF), centimeter wave (SHF), millimeter wave (EHF), and submillimeter wave. . For example, the frequency of a radio wave used for communication by GPS, Bluetooth, or CDMA (Code Division Multiple Access) is a microwave.

  (10) In the wrist device of the present invention, the radio wave is a satellite signal transmitted from a position information satellite, satellite information is acquired from the satellite signal received by the antenna, and time correction information is obtained based on the satellite information. A time correction information generation unit that generates a time information, a time information correction unit that corrects internal time information based on the time correction information, and a time information display unit that displays the internal time information, and functions as an electronic timepiece You may make it do.

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

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

  The time correction information is information necessary for correcting the internal time information. For example, the time correction information is based on time information of the position information satellite, time information calculated based on the time information, orbit information of a plurality of position information satellites. The time difference information calculated as described above.

  In the wrist device of the present invention, the electrodes of the solar cell may be formed in a mesh shape. By doing so, since the surface area of the electrode of the solar cell becomes smaller, the radio wave shielding effect by the solar cell can be made lower. Therefore, it can be expected that there will be more cases where radio waves can be received without electrically disconnecting the electrodes of the solar cell and the secondary battery when receiving radio waves, thus increasing the charging efficiency of the secondary battery. Can do.

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

  The GPS receiver 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 time other than the date can be known. For this reason, the GPS receiver 1 normally acquires only the Z count data as the current time.

  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. The GPS wristwatch is an example of a wrist device 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 3 of the first embodiment. 3A is a schematic plan view of the GPS wristwatch 3, and FIG. 3B is a schematic cross-sectional view of the GPS wristwatch 3 of FIG. 3A.

  As shown in FIG. 3A, the GPS wristwatch 3 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 3 receives a satellite signal from at least one GPS satellite 10 by manually operating the crown 14, the button 15 (A button), and the button 16 (B button), and is internally based on GPS time information. A mode for correcting the time information (time measurement mode) and a satellite signal from a plurality of GPS satellites 10 to perform positioning calculation to obtain the current location, and the internal time based on the time difference specified from the current location and the GPS time information It is configured so that it can be set to a mode for correcting information (positioning mode).

  For example, when the button 15 (A button) is pressed for several seconds (for example, 3 seconds) or longer, the GPS wristwatch 3 performs time correction processing in the time measurement mode. When the button 16 (B button) is pressed for several seconds (for example, 3 seconds) or longer, the GPS wristwatch 3 performs time correction processing (time difference correction processing) in the positioning mode.

  On the other hand, when the button 15 (A button) is pressed for a short time, the GPS wristwatch 3 displays the reception result in the previous timekeeping mode by the dial 11 and the hands 12. When the button 16 (B button) is pressed for a short time, the GPS wristwatch 3 displays the reception result in the previous positioning mode by the dial 11 and the hands 12. For example, when the reception is successful, the second hand moves to the “Y” position (10-second position), and when the reception fails, the second hand moves to the “N” position (20-second position).

  Note that the GPS wristwatch 3 can also periodically (automatically) execute the time measuring mode and the positioning mode.

  As shown in FIG. 3B, the GPS wristwatch 3 includes an exterior 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.

  Inside the exterior case 17, a step motor for driving the pointer 12, a solar cell 22, a GPS antenna 27, a secondary 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 solar cell 22 is disposed on the surface (back surface side) opposite to the time display surface of the dial plate 11, and photovoltaic power is generated by the light incident on the surface through the front glass 19 and the dial plate 11.

  The secondary battery 24 is a rechargeable secondary battery such as a lithium ion battery, and can store the power generated by the photovoltaic power generation by the solar cell 22. That is, by electrically connecting the electrode of the solar cell 22 and the electrode of the secondary battery 24, the solar cell 22 performs photovoltaic power generation, and the secondary battery 24 is charged.

  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, an inverted F antenna, or the like.

  In the present embodiment, the GPS antenna 27 is disposed on the back side of the solar cell 22 in order to improve the decoration of the GPS wristwatch 3. As a result, the GPS antenna 27 receives the satellite signal that has passed through the surface glass 19, the dial plate 11, and the solar cell 22. 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 or glass that is a material having low conductivity and magnetic permeability.

  However, since the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically connected while the solar cell 22 is generating power, the electrode of the solar cell 22 has an effect of shielding radio waves. Therefore, while the solar cell 22 is generating power, the GPS antenna 27 is difficult to receive satellite signals. On the other hand, if the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically disconnected and the electrode of the solar cell 22 is not connected anywhere (open state), the impedance of the electrode increases, and the shield The effect is reduced. Therefore, as described later, in this embodiment, the electrode of the solar cell 22 and the electrode of the secondary battery 24 can be electrically disconnected.

  The bezel 18 is made of a non-metallic material such as ceramic in order to improve satellite signal reception performance.

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

The circuit board 25 is provided with a receiving module 30 including a receiving circuit that processes satellite signals received by the GPS antenna 27, a control unit (CPU) 40 that performs step motor drive control, and the like. The receiving module 30 and the control unit (CPU) 40 are driven by power supplied from the secondary battery 24.
In the present embodiment, a secondary battery such as a lithium ion battery is used as the secondary battery 24. However, the secondary battery 24 may be a power storage unit, and may be, for example, a capacitor.

  FIG. 4A and FIG. 4B are diagrams for explaining the structure of the solar cell 22. 4A is a view of the solar cell 22 as viewed from the direction in which light enters (upward in FIG. 3B). FIG. 4B is a cross-sectional view taken along the line II-II of the solar cell 22 shown in FIG.

  As shown in FIG. 4A, the solar cell 22 has an opening 22-1 through which the pointer 12 passes and an opening 22-2 in which the display 13 is incorporated. In addition, when the pointer 12 is not present, the opening 22-1 may not be provided. If the display 13 is not present, the opening 22-2 may not be provided.

  As shown in FIG. 4B, the solar cell 22 has a structure in which amorphous silicon 228 formed on a plastic film substrate 226 is covered with protective films 220 and 227. The amorphous silicon 228 is formed such that the p-type semiconductor 222 and the n-type semiconductor 224 sandwich the i-type semiconductor 223, and the front surface (the surface facing the dial plate 11 in FIG. 3B) and the back surface of the amorphous silicon 228. A transparent electrode 221 and a metal electrode 225 are formed on each (surface facing the GPS antenna 27 and the like in FIG. 3B).

  When light that has passed through the protective film 220 and the transparent electrode 221 enters the surface of the amorphous silicon 228, electrons and holes are generated in the i-type semiconductor 223 by the energy of the light. The generated electrons and holes move in the direction of the p-type semiconductor 222 and the n-type semiconductor 224, respectively. As a result, a current flows through an external circuit connected to the transparent electrode 221 and the metal electrode 225. In this way, the solar cell 22 performs photovoltaic power generation.

  In order to increase the power generation efficiency of the solar cell 22, it is necessary to increase the amount of light incident on the surface of the amorphous silicon 228 as much as possible. Therefore, it is desirable to increase the surface area of the amorphous silicon 228 as much as possible. On the other hand, if the color and texture of the surface of the solar cell 22 are visible from the outside, the decorativeness of the GPS wristwatch 3 is not sufficient. Therefore, as shown in FIG. 3 (B), the solar cell 22 is arranged on the back side of the dial 11 so that it is difficult to be visually recognized from the outside. Since the dial 11 is visible from the outside, it is desirable to improve the appearance while transmitting light as much as possible by using a material having low transmittance.

[Circuit configuration of GPS wristwatch]
FIG. 5 is a diagram for explaining a circuit configuration of the GPS wristwatch 3 according to the first embodiment.

  The GPS wristwatch 3 includes a receiving module 30, a GPS antenna 27, a time display device 80, and a power supply device 90.

[Receiver module configuration]
The receiving module 30 is connected to a GPS antenna 27. The GPS antenna 27 is an antenna that receives satellite signals from a plurality of GPS satellites 10 as described with reference to FIG.

  The receiving module 30 includes a SAW (Surface Acoustic Wave) filter 31, an RF (Radio Frequency) unit 50, and a baseband unit 60. The SAW filter 31 performs a process of extracting a satellite signal from the signal received by the GPS antenna 27. That is, the SAW filter 31 is configured as a band-pass filter that passes a 1.5 GHz band signal.

  As will be described below, the RF unit 50 and the baseband unit 60 acquire satellite information such as orbit information and GPS time information included in the navigation message from the 1.5 GHz band satellite signal extracted by the SAW filter 31. I do.

  The RF unit 50 includes an LNA (Low Noise Amplifier) 51, a mixer 52, a VCO (Voltage Controlled Oscillator) 53, a PLL (Phase Locked Loop) circuit 54, an IF amplifier 55, an IF (Intermediate Frequency) filter 56, an ADC (ADC). (A / D converter) 57 and the like.

  The satellite signal extracted by the SAW filter 31 is amplified by the LNA 51. The satellite signal amplified by the LNA 51 is mixed with the clock signal output from the VCO 53 by the mixer 52 and down-converted to an intermediate frequency band signal. The PLL circuit 54 compares the phase of the clock signal obtained by dividing the output clock signal of the VCO 53 with the reference clock signal, and synchronizes the output clock signal of the VCO 53 with the reference clock signal. As a result, the VCO 53 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 52 is amplified by the IF amplifier 55. Here, by the mixing in the mixer 52, a high-frequency signal of several GHz is generated together with the signal in the intermediate frequency band. Therefore, the IF amplifier 55 amplifies a high frequency signal of several GHz along with the signal in the intermediate frequency band. The IF filter 56 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 56 is converted into a digital signal by an ADC (A / D converter) 57.

  The baseband unit 60 includes a DSP (Digital Signal Processor) 61, a CPU (Central Processing Unit) 62, an SRAM (Static Random Access Memory) 63, and an RTC (Real Time Clock) 64. The baseband unit 60 is connected to a crystal oscillation circuit with temperature compensation circuit (TCXO: Temperature Compensated Crystal Oscillator) 65, a flash memory 66, and the like.

  A crystal oscillation circuit (TCXO) 65 with a temperature compensation circuit generates a reference clock signal having a substantially constant frequency regardless of the temperature.

  The flash memory 66 stores time difference information. The time difference information is information in which the time difference of each of a plurality of areas into which geographic information is divided is defined.

  When set to the timekeeping mode or the positioning mode, the baseband unit 60 performs a process of demodulating the baseband signal from the digital signal (intermediate frequency band signal) converted by the ADC 57 of the RF unit 50.

  In addition, when set to the timekeeping mode or the positioning mode, the baseband unit 60 generates a local code having the same pattern as each C / A code in a satellite search process to be described later, and includes each baseband signal included in the baseband signal. Processing for correlating the C / A code and the local code is performed. Then, the baseband unit 60 adjusts the local code generation timing so that the correlation value for each local code has a peak, and if the correlation value is equal to or greater than the threshold, it synchronizes with the GPS satellite 10 of that local code (ie, The GPS satellite 10 is captured). Here, the GPS system employs a CDMA (Code Division Multiple Access) method in which all GPS satellites 10 transmit satellite signals of the same frequency using different C / A codes. Therefore, by detecting the C / A code included in the received satellite signal, the GPS satellite 10 that can be captured can be searched. Then, the baseband unit 60 demodulates the captured navigation message of the GPS satellite 10, acquires satellite information such as orbit information and GPS time information included in the navigation message, and stores it in the SRAM 63.

  The operation of the baseband unit 60 is synchronized with a reference clock signal output from a crystal oscillation circuit (TCXO) 65 with a temperature compensation circuit. The RTC 64 generates timing for processing satellite signals. The RTC 64 is counted up by a reference clock signal output from a crystal oscillation circuit (TCXO) 65 with a temperature compensation circuit.

[Configuration of time display device]
The time display device 80 includes a control unit (CPU) 40 and a crystal resonator 43.

  The control unit (CPU) 40 includes a storage unit 41, an oscillation circuit 42, a drive circuit 44, and an LCD drive circuit 45, and performs various controls.

  The control unit (CPU) 40 controls the reception module 30. That is, the control unit (CPU) 40 sends a control signal to the receiving module 30 to control the receiving operation of the receiving module 30.

  Further, the driving of the hands 12 is controlled via a drive circuit 44 in the control unit (CPU) 40. Furthermore, the drive of the display 13 is controlled via the LCD drive circuit 45 in the control unit (CPU) 40. For example, the control unit (CPU) 40 may perform control so that the current position is displayed on the display 13 in the positioning mode.

  The storage unit 41 stores internal time information. The internal time information is time information measured inside the GPS wristwatch 3. The internal time information is updated by a reference clock signal generated by the crystal resonator 43 and the oscillation circuit 42. Therefore, even if the power supply to the receiving module 30 is stopped, the internal time information can be updated and the hand movement of the hands 12 can be continued.

  When set to the timekeeping mode, the control unit (CPU) 40 controls the operation of the reception module 30, corrects the internal time information based on the GPS time information, and stores it in the storage unit 41. More specifically, the internal time information is obtained by adding a UTC parameter (a cumulative leap second that is the difference between GPS time and UTC and currently -14 seconds) to the acquired GPS time information. Time). When the positioning mode is set, the control unit (CPU) 40 controls the operation of the reception module 30 and corrects the internal time information based on the GPS time information, the UTC parameter, and the time difference data obtained from the current location. Is stored in the storage unit 41.

[Configuration of power supply device]
The power supply device 90 includes the solar cell 22 incorporated in the charge control circuit 28, the secondary battery 24, the regulator 29, and the time display device 80.

  The secondary battery 24 supplies driving power to the receiving module 30 and the time display device 80 through the regulator 29. The current generated by the photovoltaic power generation of the solar cell 22 is supplied to the secondary battery 24 through the charge control circuit 28, and the secondary battery 24 is charged.

  The charge control circuit 28 is connected between the electrode of the solar cell 22 and the electrode of the secondary battery 24, and electrically connects between the electrode of the solar cell 22 and the electrode of the secondary battery 24 based on the control signal 40A. Or cut. The control unit (CPU) 40 generates a control signal 40A based on a predetermined condition when the satellite signal is received by the GPS antenna 27.

  FIG. 6 is a diagram for explaining the configuration of the charging control circuit 28.

  The charge control circuit 28 includes a P-channel MOS transistor 28-1, an N-channel MOS transistor 28-2, and an inverter 28-3. In the P-channel MOS transistor 28-1, the source terminal and the drain terminal are connected to the transparent electrode 221 of the solar cell 22 and the + electrode of the secondary battery 24, and the gate terminal is connected to the output terminal of the inverter 28-3. ing. The N-channel MOS transistor 28-2 has a source terminal and a drain terminal connected to the metal electrode 225 of the solar cell 22 and a negative electrode of the secondary battery 24, and a gate terminal connected to an input terminal of the inverter 28-3. ing. A control signal 40A is supplied from the control unit (CPU) 40 to the input terminal of the inverter 28-3.

  When the control signal 40A is at a high level, both the P-channel MOS transistor 28-1 and the N-channel MOS transistor 28-2 are turned on. As a result, the transparent electrode 221 of the solar cell 22 and the positive electrode of the secondary battery 24 are electrically connected, and the metal electrode 225 of the solar cell 22 and the negative electrode of the secondary battery 24 are electrically connected. Therefore, the current generated by the photovoltaic power generation of the solar cell 22 is supplied to the secondary battery 24, and the secondary battery 24 is charged. At this time, since both the transparent electrode 221 and the metal electrode 225 of the solar cell 22 have a constant voltage, the solar cell 22 has an effect of shielding radio waves.

  On the other hand, when the control signal 40A is at a low level, both the P-channel MOS transistor 28-1 and the N-channel MOS transistor 28-2 are turned off. As a result, the transparent electrode 221 of the solar cell 22 and the positive electrode of the secondary battery 24 are electrically disconnected, and the metal electrode 225 of the solar cell 22 and the negative electrode of the secondary battery 24 are electrically disconnected. Therefore, photovoltaic power generation by the solar cell 22 is not performed. At this time, the transparent electrode 221 and the metal electrode 225 of the solar cell 22 are both in an open state in which no voltage is supplied, and the impedance of the electrode increases, so that the radio wave shielding effect by the solar cell 22 is reduced.

  The control unit (CPU) 40 and the charging control circuit 28 function as a connection control unit in the present invention.

  Hereinafter, the procedure of the time correction process (time measurement mode) and the time difference correction process (positioning mode) of the first embodiment will be described. The control unit (CPU) 40 can be realized by a dedicated circuit to perform various controls of these processes, but by executing a control program stored in the storage unit 41, various controls of these processes. It is also possible to perform. That is, as shown in FIG. 7, according to the control program, the control unit (CPU) 40 functions as reception control means 40-1, charge control means 40-2, time information correction means 40-3, and drive control means 40-4. Then, time correction processing (time measurement mode) and time difference correction processing (positioning mode) are executed.

[Time correction processing (time measurement mode)]
FIG. 8 is a flowchart illustrating an example of a time correction process (time measurement mode) procedure of the GPS wristwatch 3 according to the first embodiment.

  When the GPS wristwatch 3 is set to the timekeeping mode, the time adjustment process (timekeeping mode) shown in FIG. 8 is executed.

  When the time adjustment process (time measurement mode) is started, the GPS wristwatch 3 first controls the reception module 30 by the reception control means 40-1 to perform the reception process. That is, the reception control means 40-1 activates the reception module 30, and the reception module 30 starts receiving satellite signals transmitted from the GPS satellite 10 (step S10).

  And the charge control means 40-2 electrically cut | disconnects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S12). Specifically, the charge control means 40-2 supplies a low level control signal 40A to the charge control circuit 28, and the transparent electrode 221 of the solar cell 22 and the + electrode of the secondary battery 24 are electrically disconnected, The metal electrode 225 of the solar cell 22 and the negative electrode of the secondary battery 24 are electrically disconnected. As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  Next, the reception control means 40-1 starts a satellite search process (satellite search process) (step S14). In the satellite search step, the receiving module 30 performs a process of searching for a GPS satellite 10 that can be captured.

  Specifically, in the baseband unit 60, for example, when there are 30 GPS satellites 10, first, the satellite number SV is sequentially changed from 1 to 30, and the same pattern as the C / A code of the satellite number SV is obtained. Generate local code. Next, the baseband unit 60 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 baseband unit 60 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. When the correlation value is equal to or greater than a predetermined threshold, the satellite number It is determined that the SV GPS satellite 10 has been captured. Then, the baseband unit 60 stores the captured information (for example, satellite number) of each GPS satellite 10 in the SRAM 63.

  Note that the code length of the local code is 1 ms, and even when the search process of about 30 GPS satellites 10 is performed while adjusting the local code generation timing, the search of all GPS satellites 10 is completed in about 2 seconds. can do.

  Next, the reception control means 40-1 determines whether or not it is timed out based on whether or not the elapsed time since the start of the satellite search process has exceeded a predetermined time (for example, 6 seconds) set in advance (step). S18).

  If the satellite search process times out (Yes in step S16), the reception control means 40-1 forcibly ends the reception operation of the reception module 30 (step S36). When the GPS wristwatch 3 is in an environment where reception is not possible, for example, when it is indoors, there is no GPS satellite 10 that can be captured even if the satellite search process for all GPS satellites 10 is performed. If the GPS wristwatch 3 cannot detect a GPS satellite 10 that can be captured even after a predetermined time has elapsed, the GPS searching process is forcibly terminated to reduce unnecessary power consumption. be able to.

  On the other hand, when the satellite search process is completed before the time-out (Yes in Step S18), the reception control means 40-1 determines whether or not the GPS satellite 10 has been captured (Step S20).

  If the GPS satellite 10 cannot be captured (No in step S20), the reception control means 40-1 starts the satellite search process again (step S14).

  On the other hand, if the GPS satellite 10 can be captured (Yes in step S20), the reception control means 40-1 starts acquiring satellite information (particularly GPS time information) of the captured GPS satellite 10 (step S20). S22). Specifically, the baseband unit 60 performs processing for demodulating the navigation message from each captured GPS satellite and acquiring Z count data for three subframes. Then, the baseband unit 60 stores the acquired GPS time information in the SRAM 63. If all the acquired Z count data for the three subframes are correct, the reception control unit 40-1 ends the acquisition of the satellite information.

  If the reception control means 40-1 times out before completing the acquisition of the satellite information of one or more GPS satellites 10 (Yes in step S24), it starts the satellite search process again (step S14). For example, since the reception level of the satellite signal from the GPS satellite 10 is low, it may be possible to time out without correctly demodulating the satellite information of one or more GPS satellites 10.

  On the other hand, if the acquisition of the satellite information of one or more GPS satellites 10 can be completed before the time-out (in the case of Yes in step S26), the reception control means 40-1 The satellite information (GPS time information) is read from the SRAM 63, and the receiving operation of the receiving module 30 is terminated (step S28).

  Next, the charge control means 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S30). Specifically, the charging control means 40-2 supplies a high-level control signal 40A to the charging control circuit 28, and the transparent electrode 221 of the solar cell 22 and the + electrode of the secondary battery 24 are electrically connected, The metal electrode 225 of the solar cell 22 and the negative electrode of the secondary battery 24 are electrically connected. As a result, photovoltaic power generation by the solar cell 22 is resumed.

  And the time information correction means 40-3 corrects the internal time information memorize | stored in the memory | storage part 41 based on the GPS time information acquired from the receiving module 30 (step S32).

  Finally, the drive control means 40-4 controls the drive circuit 44 or the LCD drive circuit 45 based on the corrected internal time information, and the time display is corrected (step S34).

  In addition, also when reception operation | movement of the receiving module 30 is forcedly complete | finished (step S36), the charge control means 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24 similarly to step S30. And the photovoltaic power generation by the solar cell 22 is resumed. (Step S38).

[Time difference correction processing (positioning mode)]
FIG. 9 is a flowchart illustrating an example of a time difference correction process (positioning mode) procedure of the GPS wristwatch 3 according to the first embodiment. In the following description, the description of the same processing as the time correction processing (time measurement mode) procedure is omitted or simplified.

  When the GPS wristwatch 3 is set to the positioning mode, the time difference correction process (positioning mode) shown in FIG. 9 is executed.

  When the time difference correction process (positioning mode) is started, the GPS wristwatch 3 first performs reception processing by controlling the reception module 30 by the reception control means 40-1. That is, the reception control means 40-1 activates the reception module 30, and the reception module 30 starts receiving the satellite signal transmitted from the GPS satellite 10 (step S100).

  And the charge control means 40-2 electrically cut | disconnects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S102). As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  Next, the reception control means 40-1 starts a satellite search process (satellite search process) (step S104).

  Next, the reception control means 40-1 determines whether or not it is timed out based on whether or not the elapsed time from the start of the satellite search process exceeds a predetermined time set in advance (step S106).

  If the satellite search process times out (Yes in step S106), the reception control unit 40-1 forcibly ends the reception operation of the reception module 30 (step S132).

  On the other hand, if the satellite search process is completed before the time-out (Yes in step S108), whether or not the reception control means 40-1 has been able to capture a predetermined number (N) or more of the GPS satellites 10. Is determined (step S110). Here, in order to specify the three-dimensional position (x, y, z) of the GPS wristwatch 3, x, y, z are three unknowns. Therefore, in order to calculate the three-dimensional position (x, y, z) of the GPS wristwatch 3, 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 3 and the GPS time information is also unknown, GPS time information and orbit information of four or more GPS satellites 10 are required.

  If N (for example, four) or more GPS satellites 10 cannot be captured (No in step S110), the reception control means 40-1 starts the satellite search process again (step S104).

  On the other hand, when N (for example, four) or more GPS satellites 10 can be captured (Yes in step S110), the reception control means 40-1 acquires satellite information (particularly GPS time) of the captured GPS satellites 10. Acquisition of information and orbit information) is started (step S112). Specifically, the baseband unit 60 performs a process of demodulating each captured navigation message from each GPS satellite and obtaining Z count data and ephemeris parameters. And the baseband part 60 memorize | stores the acquired GPS time information and orbit information in SRAM63.

  The reception control means 40-1 starts the satellite search process again when time-out occurs before acquiring satellite information of N (for example, four) or more GPS satellites 10 (Yes in step S114) (step S104). ). For example, since the reception level of the satellite signal from the GPS satellite 10 is low, it may be possible to time out without correctly demodulating the satellite information of N (for example, four) or more GPS satellites 10.

  On the other hand, when acquisition of satellite information of N (for example, four) or more GPS satellites 10 can be completed before the time-out (in the case of Yes in step S116), the baseband unit 60 acquires the captured GPS satellites. A set of N (for example, 4) GPS satellites 10 is selected from 10 and positioning calculation is started (step S118).

  Specifically, the baseband unit 60 reads the satellite information (GPS time information and orbit information) of the selected N (for example, four) GPS satellites 10 from the SRAM 63, performs positioning calculation, and obtains position information (with GPS). (Latitude and longitude of the place where the wristwatch 3 is located).

  Then, the baseband unit 60 refers to the time difference information stored in the flash memory 66 and acquires time difference data of a place where the GPS wristwatch 3 is located based on the position information and the positioning error. And the baseband part 60 will complete | finish positioning calculation, if time difference data can be acquired.

  The reception control means 40-1 starts the satellite search process again (step S104) when it times out before completing the positioning calculation (Yes in step S120).

  On the other hand, if the positioning calculation can be completed before the time-out (Yes in step S122), the reception control means 40-1 reads out the GPS time information of at least one GPS satellite 10 from the SRAM 63 together with the time difference data. Then, the receiving operation of the receiving module 30 is terminated (step S124).

  Next, the charge control means 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S126). As a result, photovoltaic power generation by the solar cell 22 is resumed.

  And the time information correction means 40-3 corrects the internal time information memorize | stored in the memory | storage part 41 based on the GPS time information and time difference data acquired from the receiving module 30 (step S128).

  Finally, the drive control means 40-4 controls the drive circuit 44 or the LCD drive circuit 45 based on the corrected internal time information, and the time display (time difference) is corrected (step S130).

  Even when the receiving operation of the receiving module 30 is forcibly terminated (step S132), the charging control means 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24 as in step S126. And the photovoltaic power generation by the solar cell 22 is resumed. (Step S134).

[Effect of the first embodiment]
The distance at which an electromagnetic field incident on a material is attenuated to 1 / e is called skin depth, and a material with a smaller skin depth is less likely to transmit radio waves. The skin depth d of a conductor with magnetic permeability μ and conductivity σ with respect to a radio wave of frequency f is given by the following equation.

  According to Expression (1), the skin depth d decreases as the frequency f of radio waves increases. That is, the higher the frequency f, the more difficult it is to pass radio waves. For microwaves with a high frequency, the influence on the skin depth is particularly large. That is, the shielding effect of the transparent electrode 221 and the metal electrode 225 of the solar cell 22 greatly acts on the microwave.

  In the GPS wristwatch 3 according to the first embodiment, as shown in FIGS. 8 and 9, during the reception of the satellite signal, the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically disconnected. By reducing the shielding effect of the solar cell 22, radio waves are not blocked by the solar cell 22, and assured reception can be ensured by passing the solar cell 22 as much as possible. Therefore, even if the GPS antenna 27 is disposed inside the wristwatch on the back side of the solar cell 22, reliable reception can be maintained. Therefore, according to the GPS wristwatch 3 of the first embodiment, restrictions on antenna arrangement can be relaxed, so that decorativeness and wearability can be improved.

  Further, according to the first embodiment, since reliable reception can be maintained even if the GPS antenna 27 is arranged inside the wristwatch on the back side of the solar cell 22, the GPS is easy to use and has good decorativeness. A wristwatch can be provided.

2-2. Second Embodiment In the GPS wristwatch 3 according to the first embodiment, the photovoltaic operation is stopped by cutting between the electrode of the solar cell 22 and the electrode of the secondary battery 24 of the solar cell 22 during the receiving operation. When the reception condition is extremely good, the satellite signal may be received even if the shielding effect by the solar cell 22 is exhibited. Therefore, in the GPS wristwatch 3 of the second embodiment, the photovoltaic operation of the solar cell 22 is controlled based on the reception level of the satellite signal.

  Therefore, in the GPS wristwatch 3 according to the second embodiment, the baseband unit 60 detects the reception level of the satellite signal transmitted from each captured GPS satellite 10. That is, the baseband unit 60 functions as a reception level detection unit in the present invention. Then, the charging control unit 40-2 controls to electrically connect or disconnect between the electrode of the solar cell 22 and the electrode of the secondary battery 24 based on the detected reception level of the satellite signal.

  The structure and circuit configuration of the GPS wristwatch 3 according to the second embodiment are shown in FIGS. 3 (A), 3 (B), 4 (A), 4 (B), 5 and 6. Since it may be the same as the structure and circuit configuration of the GPS wristwatch 3 of the embodiment, the description thereof is omitted.

  Hereinafter, the procedure of the time correction process (time measurement mode) and the time difference correction process (positioning mode) of the second embodiment will be described. As shown in FIG. 10, according to the control program, the control unit (CPU) 40 causes the reception control means 40-1, the charge control means 40-2, the time information correction means 40-3, the drive control means 40-4, and the reception state determination. It functions as the means 40-5, and the following time correction process (time measurement mode) and time difference correction process (positioning mode) are executed. Each unit shown in FIG. 10 is the same as each unit shown in FIG. 7 except for the reception state determination unit 40-5.

  FIG. 11 is a flowchart illustrating an example of a time correction process (time measurement mode) procedure of the GPS wristwatch 3 according to the second embodiment.

  The time correction process (time measurement mode) procedure shown in FIG. 11 is shown in FIG. 8 except that the process in step S12 in FIG. 8 is deleted and the processes in steps S40, S42 and S44 are added. This is the same as the time correction processing (time measurement mode) procedure of the first embodiment. Therefore, description of processes other than steps S40, S42, and S44 is omitted.

  When the GPS wristwatch 3 of the second embodiment is set to the timekeeping mode, the time correction process (timekeeping mode) shown in FIG. 11 is executed.

  When the GPS satellite 10 can be captured (Yes in step S20), the reception control means 40-1 reads out the reception level of the satellite signal transmitted from each captured GPS satellite 10 from the SRAM 63 (step S40). ). Specifically, the baseband unit 60 calculates the power of the signal obtained by mixing the local code and the baseband signal with the same pattern as the C / A code of each captured GPS satellite 10, and after detecting the reception level, the SRAM 63 To remember. Then, the reception control means 40-1 reads the reception level of the satellite signal stored in the SRAM 63.

  Next, the reception state determination unit 40-5 determines whether or not the reception level of the satellite signal detected by the baseband unit 60 is equal to or higher than a predetermined threshold (step S42). Specifically, the reception level of the satellite signal stored in the SRAM 63 is read to determine whether or not it is equal to or greater than a threshold value. Here, the threshold is set to a signal level at which the receiving module 30 can receive satellite signals and acquire satellite information. In the positioning mode to be described later, it is necessary to acquire satellite information by receiving satellite signals from N (for example, four) GPS satellites 10, whereas in the timekeeping mode, from one GPS satellite 10 Since it is only necessary to receive satellite signals and acquire satellite information, the time measurement mode has a higher probability that necessary satellite information can be acquired even in the same reception state as the positioning mode. Accordingly, the threshold of the satellite signal reception level in the time measurement mode may be set lower than the threshold of the satellite signal reception level in the positioning mode.

  If the reception level is higher than the threshold (No in step S42), the reception control means 40-1 starts acquiring satellite information (particularly GPS time information) of the captured GPS satellite 10 (step S22).

  On the other hand, when the reception level is equal to or lower than the threshold value (Yes in step S42), the charging control unit 40-2 electrically disconnects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S44). . As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  And the process after step S22 is performed and a time correction process (time measurement mode) is complete | finished.

  FIG. 12 is a flowchart illustrating an example of a time difference correction process (positioning mode) procedure of the GPS wristwatch 3 according to the second embodiment.

  The time difference correction process (positioning mode) procedure shown in FIG. 12 is the same as that shown in FIG. 9 except that the process in step S102 in FIG. 9 is deleted and the processes in steps S140, S142, and S144 are added. This is the same as the time difference correction processing (positioning mode) procedure of one embodiment. Therefore, description of processes other than steps S140, S142, and S144 is omitted.

  When the GPS wristwatch 3 of the second embodiment is set to the positioning mode, the time difference correction process (positioning mode) shown in FIG. 12 is executed.

  When N (for example, four) or more GPS satellites 10 can be acquired (Yes in step S110), the baseband unit 60 receives the reception level of the satellite signal transmitted from each acquired GPS satellite 10 Is detected and stored in the SRAM 63. And the reception control means 40-1 reads the reception level of the satellite signal memorize | stored in SRAM63 (step S140).

  Next, the reception state determination unit 40-5 determines whether or not the reception level of the satellite signal detected by the baseband unit 60 is equal to or higher than a predetermined threshold (step S142).

  If the reception level is higher than the threshold (No in step S142), the reception control means 40-1 starts acquiring satellite information (particularly GPS time information and orbit information) of the captured GPS satellite 10 (step S112). ). In the timekeeping mode, satellite information from one GPS satellite 10 may be received to acquire satellite information, whereas in the positioning mode, satellite signals from N (for example, four) GPS satellites 10 are acquired. Since it is necessary to receive and acquire satellite information, the positioning mode has a higher probability that necessary satellite information cannot be acquired even in the same reception situation as the time measurement mode. Therefore, the threshold of the satellite signal reception level in the positioning mode may be set higher than the threshold of the satellite signal reception level in the time measurement mode.

  On the other hand, when the reception level is equal to or lower than the threshold value (Yes in step S42), the charging control unit 40-2 electrically disconnects the electrode of the solar cell 22 and the electrode of the secondary battery 24 (step S144). . As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  And the process after step S112 is performed and a time difference correction process (positioning mode) is complete | finished.

[Effects of Second Embodiment]
According to the GPS wristwatch 3 of the second embodiment, in addition to the same effects as the GPS wristwatch 3 of the first embodiment, the following effects are obtained.

  In the GPS wristwatch 3 of the second embodiment, when the reception level is higher than the threshold value, the satellite signal is received while the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically connected. . Therefore, according to the GPS wristwatch 3 of the second embodiment, when the reception condition is very good, the secondary battery 24 can be charged by the photovoltaic power generation of the solar cell 22 even during the reception operation.

  Further, in the GPS wristwatch 3 of the second embodiment, as shown in FIGS. 11 and 12, when the reception level of the satellite signal becomes lower than the threshold value during the receiving operation, the solar cell 22 and the electrode of the solar cell 22 are connected. The satellite signal is received in a state where the electrodes of the secondary battery 24 are electrically disconnected. Therefore, according to the GPS wristwatch 3 of the second embodiment, reliable reception can be maintained even when the reception state deteriorates during reception.

  That is, in the GPS wristwatch 3 of the second embodiment, the photovoltaic power generation operation of the solar cell 22 is appropriately controlled according to the reception level of the satellite signal even during the reception of the satellite signal. The power generation efficiency of the cell 22 can be optimized.

2-3. Third Embodiment According to Equation (1), the skin depth d decreases as the electrical conductivity σ of the conductor increases. That is, a conductor having a higher conductivity σ is less likely to transmit radio waves.

  On the other hand, the amorphous silicon 228 included in the solar cell 22 is different in conductivity (photoconductivity) when performing photovoltaic power generation and conductivity (dark conductivity) when not performing photovoltaic power generation. The photoconductivity is about 1000 to 100,000 times the dark conductivity. Therefore, when the solar cell 22 is performing photovoltaic power generation, it is difficult for radio waves to pass through, so the GPS antenna 27 is difficult to receive radio waves sent from the GPS satellite 10. Conversely, when the solar cell 22 is not generating photovoltaic power, it is easy to transmit radio waves, and thus the GPS antenna 27 can easily receive radio waves transmitted from the GPS satellite 10.

  That is, it becomes easy to receive the radio wave transmitted from the GPS satellite 10 in a state where the electrical conductivity where the solar cell 22 is not performing photovoltaic power generation is small.

  And the output electric current of the solar cell 22 becomes high, so that the illumination intensity of the light which injects into the solar cell 22 is high. That is, according to the illuminance of light incident on the solar cell 22, reliable reception is maintained by controlling electrical connection or disconnection between the electrode of the solar cell 22 and the electrode of the secondary battery during the reception operation. However, the power generation efficiency of the solar cell can be optimized.

  Therefore, in the GPS wristwatch 3 according to the third embodiment, the solar cell 22 functions as an optical sensor in which the illuminance of light incident on the solar cell 22 and the output current change proportionally. Illuminance can be detected by using the solar cell 22 as an illuminance detector. In the GPS wristwatch 3 of the third embodiment, the illuminance of light incident on the solar cell 22 is detected by converting the output current of the solar cell 22 at the time of reception into a voltage and detecting the voltage value. Based on the detected voltage value of the solar cell 22, the photovoltaic power generation operation of the solar cell 22 is controlled.

  The GPS wristwatch 3 of the third embodiment has the same structure as that of the GPS wristwatch 3 of the first embodiment shown in FIGS. 3 (A), 3 (B), 4 (A), and 4 (B). Since this is the same, the description thereof is omitted. The circuit configuration of the GPS wristwatch 3 of the third embodiment is the same as the circuit configuration of the GPS wristwatch 3 of the first embodiment shown in FIG. 5 except for the configuration of the charging control circuit 28. Description is omitted.

  FIG. 13 is a diagram for explaining the configuration of the charge control circuit 28 of the third embodiment.

  The charge control circuit 28 includes a P-channel MOS transistor 28-1, an N-channel MOS transistor 28-2, an inverter 28-3, and a current detection circuit 32. Since the connections and functions of the P-channel MOS transistor 28-1, the N-channel MOS transistor 28-2, and the inverter 28-3 are the same as those in FIG. 6, description thereof is omitted.

  The current detection circuit 32 includes a resistor 32-1, a differential amplifier 32-2, and a switch circuit 32-3. The switch circuit 32-3 connects the transparent electrode 221 of the solar cell 22 to the source terminal of the P-channel MOS transistor 28-1 or one end of the resistor 32-1 by the control signal 40B. The other end of the resistor 32-1 is connected to the source terminal of the P-channel MOS transistor 28-1. The differential amplifier 32-2 is connected to both ends of the resistor 32-1.

  The control unit (CPU) 40 generates a control signal 40B for controlling the transparent electrode 221 of the solar cell 22 to be connected to one end of the resistor 32-1 at a predetermined timing in the time measuring mode or the positioning mode. Then, the differential amplifier 32-2 detects a voltage drop across the resistor 32-1 caused by a current flowing through the resistor 32-1, and generates a detection voltage signal 32A. The charging control means 60-2 acquires the detection voltage signal 32A and generates a control signal 40B for controlling the transparent electrode 221 of the solar cell 22 to be connected to the source terminal of the P-channel MOS transistor 28-1. And the charging control means 60-2 produces | generates the control signal 40A based on the acquired detection voltage signal 32A, and controls so that the electrode of the solar cell 22 and the electrode of the secondary battery 24 may be electrically connected or disconnected. .

  Hereinafter, the procedure of the time correction process (time measurement mode) and the time difference correction process (positioning mode) of the third embodiment will be described. Similarly to the control unit (CPU) 40 in the first embodiment, the control unit (CPU) 40 in the third embodiment uses a control program to receive the reception control unit 40-1 and the charging control unit 40-2 shown in FIG. The time information correction means 40-3 and the drive control means 40-4 function, and the following time correction processing (time measurement mode) and time difference correction processing (positioning mode) are executed.

  FIG. 14 is a flowchart illustrating an example of a time correction process (time measurement mode) procedure of the GPS wristwatch 3 according to the third embodiment.

  The time correction process (time measurement mode) procedure shown in FIG. 14 is shown in FIG. 8 except that the process in step S12 in FIG. 8 is deleted and the processes in steps S50, S52, and S54 are added. This is the same as the time correction processing (time measurement mode) procedure of the first embodiment. Therefore, description of processes other than steps S50, S52, and S54 is omitted.

  When the GPS wristwatch 3 of the third embodiment is set to the timekeeping mode, the time adjustment process (timekeeping mode) shown in FIG. 14 is executed.

  When reception is started, the current detection circuit 32 of the charge control circuit 28 detects the illuminance of light incident on the solar cell 22 under the control of the charge control output means 40-2 (step S50). Specifically, the charge control output unit 40-2 generates a control signal 40B for controlling the transparent electrode 221 of the solar cell 22 to be connected to one end of the resistor 32-1. The differential amplifier 32-2 of the current detection circuit 32 detects a voltage drop across the resistor 32-1 caused by the current flowing through the resistor 32-1, and generates a detection voltage signal 32A.

  Next, the charging control output unit 40-2 determines whether or not the illuminance of light incident on the solar cell 22 is equal to or higher than a threshold value (step S52). Specifically, the charging control output unit 40-2 determines the illuminance of light incident on the solar cell 22 from the voltage value of the detection voltage signal 32A. Here, the threshold is set to the illuminance of light incident on the solar cell 22 so that the GPS antenna 27 can receive satellite signals and the receiving module 30 can reliably acquire satellite information. As described above, in the time measurement mode, there is a higher probability that necessary satellite information can be acquired even in the same reception situation as in the positioning mode. Therefore, the threshold value of the illuminance of light incident on the solar cell 22 in the time measurement mode may be set higher than the threshold value of the illuminance of light incident on the solar cell 22 in the positioning mode.

  If the illuminance of the light incident on the solar cell 22 is lower than the threshold (No in step S52), the reception control means 40-1 starts the satellite search process (step S14).

  On the other hand, when the illuminance of light incident on the solar cell 22 is equal to or greater than the threshold (Yes in step S52), the charging control unit 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24. Disconnect (step S54). As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  And the process after step S14 is performed and a time correction process (time measurement mode) is complete | finished.

  If the baseband unit 60 cannot capture the GPS satellite 10 (No in step S20), or if time-out occurs before the acquisition of the satellite information of one or more GPS satellites 10 ends (Yes in step S24). In this case, in step S50, the illuminance of light incident on the solar cell 22 is detected again by the voltage detection circuit 32, and the subsequent processing is performed.

  FIG. 15 is a flowchart illustrating an example of a time difference correction process (positioning mode) procedure of the GPS wristwatch 3 according to the third embodiment.

  The time difference correction process (positioning mode) procedure shown in FIG. 15 is the same as that shown in FIG. 9 except that the process in step S102 in FIG. 9 is deleted and the processes in steps S150, S152, and S154 are added. This is the same as the time difference correction processing (positioning mode) procedure of one embodiment. Therefore, description of processes other than steps S150, S152, and S154 is omitted.

  When the GPS wristwatch 3 of the third embodiment is set to the positioning mode, the time adjustment process (time measurement mode) shown in FIG. 15 is executed.

  When reception is started, the current detection circuit 32 of the charge control circuit 28 detects the illuminance of light incident on the solar cell 22 under the control of the charge control output means 40-2 (step S150).

  Next, the charging control output unit 40-2 determines whether or not the illuminance of light incident on the solar cell 22 is equal to or higher than a threshold value (step S152). As described above, in the positioning mode, there is a higher probability that necessary satellite information cannot be acquired even in the same reception situation as the timekeeping mode. Therefore, the illuminance threshold value of the light incident on the solar cell 22 in the positioning mode may be set lower than the illuminance threshold value of the light incident on the solar cell 22 in the time measuring mode.

  If the illuminance of the light incident on the solar cell 22 is lower than the threshold (No in step S152), the reception control means 40-1 starts the satellite search process (step S104).

  On the other hand, when the illuminance of the light incident on the solar cell 22 is equal to or higher than the threshold value (Yes in step S152), the charging control unit 40-2 electrically connects the electrode of the solar cell 22 and the electrode of the secondary battery 24. Disconnect (step S154). As a result, the radio wave shielding effect by the solar cell 22 is reduced, and the GPS antenna 27 can easily receive satellite signals.

  And the process after step S104 is performed and a time difference correction process (positioning mode) is complete | finished.

  The baseband unit 60 cannot capture N (for example, 4) or more GPS satellites 10 (in the case of No in step S110) or the satellite information of N (for example, 4) or more GPS satellites 10 If time-out occurs before the acquisition is completed (Yes in step S114), in step S150, the illuminance of light incident on the solar cell 22 is detected again by the voltage detection circuit 32, and the subsequent processing is performed.

  Note that the voltage detection circuit 32 indirectly detects the illuminance of light incident on the solar cell 22 by detecting the output current of the solar cell 22. That is, the voltage detection circuit 32 functions as an illuminance detection unit in the present invention. Further, the voltage detection circuit 32 can be replaced with an arbitrary circuit that directly or indirectly detects the illuminance of light incident on the solar cell.

[Effect of the third embodiment]
According to the GPS wristwatch 3 of the third embodiment, in addition to the same effects as the GPS wristwatch 3 of the first embodiment, the following effects can be obtained.

  In the GPS wristwatch 3 of the third embodiment, as shown in FIGS. 14 and 15, the illuminance of light incident on the solar cell 22 is detected at the start of reception, and the photovoltaic operation of the solar cell 22 is performed according to the detection result. To control. Specifically, when the illuminance of light incident on the solar cell 22 at the start of reception is equal to or greater than a threshold value, the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically disconnected. In the GPS wristwatch 3 of the third embodiment, the illuminance of light incident on the solar cell 22 is detected even during reception, and the photovoltaic operation of the solar cell 22 is controlled according to the detection result. Specifically, when the illuminance of light incident on the solar cell 22 during reception becomes equal to or higher than a threshold value, the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically disconnected.

  That is, according to the GPS wristwatch 3 of the third embodiment, when the solar cell 22 exhibits a high shielding effect by performing photovoltaic power generation, by preventing the solar cell 22 from performing photovoltaic power generation. , Reliable reception can be maintained.

2-4. Fourth Embodiment A GPS wristwatch 3 according to the fourth embodiment has a GPS structure according to the first embodiment shown in FIGS. 3 (A), 3 (B), 4 (A), and 4 (B). Since the structure of the wristwatch 3 may be the same, the description thereof is omitted. The circuit configuration of the GPS wristwatch 3 of the fourth embodiment may be the same as the circuit configuration of the GPS wristwatch 3 of the first embodiment shown in FIG.

  In the GPS wristwatch 3 of the fourth embodiment, similarly to the GPS wristwatch 3 of the second embodiment, the charging control means 60-2 is based on the reception level of the satellite signal transmitted from the captured GPS satellite 10. Control is performed so that the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically connected or disconnected.

  Further, in the GPS wristwatch 3 of the fourth embodiment, the charging control means 60-2 is based on the illuminance of light incident on the solar cell 22 as in the GPS wristwatch 3 of the third embodiment. And the electrode of the secondary battery 24 are controlled to be electrically connected or disconnected.

  FIG. 16 is a flowchart illustrating an example of a time correction process (time measurement mode) procedure of the GPS wristwatch 3 according to the fourth embodiment.

  The time correction process (time measurement mode) procedure shown in FIG. 16 is such that the process of step S12 of FIG. 8 is deleted and the processes of steps S40, S42 and S44 and the processes of steps S50, S52 and S54 are added. Except for, the procedure is the same as the time correction processing (time measurement mode) procedure of the first embodiment shown in FIG. Further, the processes in steps S40, S42 and S44 in FIG. 16 are the same as the processes in steps S40, S42 and S44 of the time adjustment process (time measurement mode) procedure of the GPS wristwatch 3 of the second embodiment shown in FIG. It is. Further, the processing in steps S50, S52 and S54 in FIG. 16 is the same as the processing in steps S50, S52 and S54 in the time adjustment processing (time measurement mode) procedure of the GPS wristwatch 3 of the third embodiment shown in FIG. It is. Therefore, the description of the time correction processing (time measurement mode) procedure in FIG. 16 is omitted.

  FIG. 17 is a flowchart illustrating an example of a time difference correction process (positioning mode) procedure of the GPS wristwatch 3 according to the fourth embodiment.

  The time difference correction process (positioning mode) procedure shown in FIG. 17 is such that the process of step S102 of FIG. 9 is deleted and the processes of steps S140, S142, and S144 and the processes of steps S150, S152, and S154 are added. Except for this, the procedure is the same as the time correction processing (time measurement mode) procedure of the first embodiment shown in FIG. Also, the processing in steps S140, S142, and S144 in FIG. 17 is the same as the processing in steps S140, S142, and S144 in the time adjustment processing (time measurement mode) procedure of the GPS wristwatch 3 in the second embodiment shown in FIG. It is. Furthermore, the processing of steps S150, S152, and S154 in FIG. 17 is the same as the processing of steps S150, S152, and S154 of the time adjustment processing (time measurement mode) procedure of the GPS wristwatch 3 of the third embodiment shown in FIG. It is. Therefore, the description of the time difference correction processing (positioning mode) procedure in FIG. 17 is omitted.

  Note that the control unit (CPU) 40 in the fourth embodiment is similar to the control unit (CPU) 40 in the second embodiment by the control program according to the reception control unit 40-1 and the charge control unit 40 shown in FIG. -2, functions as time information correction means 40-3, drive control means 40-4 and reception state determination means 40-5, and executes time correction processing (time measurement mode) and time difference correction processing (positioning mode).

[Effect of Fourth Embodiment]
According to the GPS wristwatch 3 of the fourth embodiment, in addition to the same effects as the GPS wristwatch 3 of the first to third embodiments, the following effects can be obtained.

  In the time adjustment process (time measurement mode) procedure of the GPS wristwatch 3 of the fourth embodiment, the charging control means 60-2 also includes the case where the reception level of the satellite signal is equal to or lower than the threshold value (Yes in step S42). Even when the illuminance of light incident on the solar cell 22 is greater than or equal to the threshold value (Yes in step S52), control is performed so that the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically disconnected. Therefore, according to the GPS wristwatch 3 of the fourth embodiment, it is possible to expect an improvement effect even better than the reception situation improvement effect in the GPS wristwatch 3 of the second embodiment or the third embodiment.

2-5. Fifth Embodiment The GPS wristwatch 3 of the fifth embodiment is different from the GPS wristwatch 3 of the first to fourth embodiments in the structure of the solar cell 22. The structure of the GPS wristwatch 3 of the fifth embodiment other than the solar cell 22 is the GPS of the first embodiment shown in FIGS. 3 (A), 3 (B), 4 (A), and 4 (B). Since it may be the same as the structure of the wristwatch 3, description thereof is omitted. The circuit configuration of the GPS wristwatch 3 of the fifth embodiment may be the same as the circuit configuration of the GPS wristwatch 3 of the first embodiment shown in FIG.

  FIGS. 18A and 18B are views for explaining the structure of the solar cell 22 in the GPS wristwatch 3 of the fifth embodiment. FIG. 18A is a view of the solar cell 22 as viewed from the direction in which light is incident (upward in FIG. 3B). FIG. 18B is a cross-sectional view taken along the line II-II of the solar cell 22 shown in FIG.

  As shown in FIG. 18A, the solar cell 22 has an opening 22-1 for passing the pointer 12 and an opening 22-2 in which the display 13 is incorporated. In addition, when the pointer 12 is not present, the opening 22-1 may not be provided. If the display 13 is not present, the opening 22-2 may not be provided.

  As shown in FIGS. 18A and 18B, in the solar cell 22, the transparent electrode 221 and the metal electrode 225 on the upper surface of the GPS antenna 27 are both formed in a mesh shape. Since the surface area of the transparent electrode 221 and the metal electrode 225 is small on the upper surface of the GPS antenna 27, the radio wave shielding effect is lowered. Note that structures other than the transparent electrode 221 and the metal electrode 225 of the solar cell 22 illustrated in FIG. 18B are the same as those in FIG.

  In the GPS wristwatch 3 according to the fifth embodiment, the charging control means 60-2 is configured so that the solar cell 22 is transparent based on given conditions (such as the reception level of satellite signals and the illuminance of light incident on the solar cell 22). Control is performed so that the electrode 221 and the positive electrode of the secondary battery 24 and the metal electrode 225 of the solar cell 22 and the negative electrode of the secondary battery 24 are electrically connected or disconnected simultaneously.

  Note that the time correction processing (time measurement mode) procedure of the GPS wristwatch 3 of the fifth embodiment is the same as that of the first to fourth embodiments shown in FIGS. 8, 11, 14, and 16. 3 may be the same as any one of the time correction processing (time measurement mode) procedure of 3, and the description thereof is omitted.

  Further, the time difference correction processing (positioning mode) procedure of the GPS wristwatch 3 of the fifth embodiment is the same as that of the GPS wristwatch 3 of the first to fourth embodiments shown in FIGS. 9, 12, 15, and 17. The time difference correction processing (positioning mode) procedure may be the same as that in FIG.

[Effect of Fifth Embodiment]
According to the GPS wristwatch 3 of the fifth embodiment, in addition to the same effects as the GPS wristwatch 3 of the first to fourth embodiments, the following effects can be obtained.

  In the GPS wristwatch 3 of the fifth embodiment, the surface areas of the transparent electrode 221 and the metal electrode 225 of the solar cell 22 on the top surface of the GPS antenna 27 are smaller than those of the GPS wristwatch 3 of the first to fourth embodiments. Therefore, the radio wave shielding effect by the solar cell 22 is lower. Therefore, according to the GPS wristwatch 3 of the fifth embodiment, compared with the GPS wristwatch 3 of the first to fourth embodiments, the electrode of the solar cell 22 and the secondary battery during the reception operation of the reception module 30. Since it can be expected that the number of satellite signals can be received without electrically disconnecting the 24 electrodes, the charging efficiency of the secondary battery 24 can be increased.

  In addition, this invention is not limited to this embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention.

  For example, in the first to fifth embodiments, the electrode of the solar cell 22 and the electrode of the secondary battery 24 are electrically connected before the reception starts and after the reception ends (that is, a state other than during reception). The secondary battery 24 may be always charged. However, when the secondary battery 24 is fully charged, the secondary battery 24 is electrically disconnected from the electrode of the solar cell 22 and the electrode of the secondary battery 24. A function may be provided to stop charging.

  Further, for example, in the fifth embodiment, the case where the transparent electrode 221 and the metal electrode 225 of the solar cell 22 on the top surface of the GPS antenna 27 are formed in a mesh shape has been described as an example. Both of the metal electrodes 225 may be formed in a mesh shape.

  In addition, according to Formula (1), it is easy to receive a shield effect, so that the frequency of an electromagnetic wave is high. In the GPS wristwatch 3 of each of the above-described embodiments, the influence of the shielding effect is large because a satellite signal in the 1.5 GHz band is received, but by appropriately controlling the photovoltaic operation of the solar cell 22 during the reception operation, It is possible to maintain reliable reception.

  For example, each of the above-described embodiments has been described by taking a GPS wristwatch as an example. However, the wrist device of the present invention is not limited to a GPS wristwatch, and may be another type of wrist device. As another type of list device, for example, a list type communication device such as Bluetooth or CDMA is conceivable. The present invention can also be applied to a solar radio timepiece that receives long waves.

  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.

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. 4A and 4B are views for explaining the structure of a solar cell. The figure for demonstrating the circuit structure of the wristwatch with GPS of 1st Embodiment. The figure for demonstrating the structure of a charge control circuit. The figure for demonstrating the structure of the control part (CPU) of 1st Embodiment. The flowchart which shows an example of the time correction processing procedure of 1st Embodiment. The flowchart which shows an example of the time difference correction process sequence of 1st Embodiment. The figure for demonstrating the structure of the control part (CPU) of 2nd Embodiment. The flowchart which shows an example of the time correction processing procedure of 2nd Embodiment. The flowchart which shows an example of the time difference correction processing procedure of 2nd Embodiment. The figure for demonstrating the structure of the charge control circuit of 3rd Embodiment. The flowchart which shows an example of the time correction process procedure of 3rd Embodiment. The flowchart which shows an example of the time difference correction process sequence of 3rd Embodiment. The flowchart which shows an example of the time correction processing procedure of 4th Embodiment. The flowchart which shows an example of the time difference correction process sequence of 4th Embodiment. FIGS. 18A and 18B are views for explaining an example of the structure of the solar cell of the fifth embodiment.

Explanation of symbols

1 GPS receiver, 3 GPS wristwatch, 10 GPS satellite, 11 dial, 12 pointer, 13 display, 14 crown, 15 button, 16 button, 17 exterior case, 18 bezel, 19 surface glass, 20 motor coil, 22 solar Cell, 24 secondary battery, 25 circuit board, 26 back cover, 27 GPS antenna, 28 charge control circuit, 28-1 P-channel MOS transistor, 28-2 N-channel MOS transistor, 28-3 inverter, 29 regulator, 30 reception module, 31 SAW filter, 32 current detection circuit, 32-1 resistor, 32-2 differential amplifier, 32-3 switch circuit, 40 control unit (CPU), 41 storage unit, 42 oscillation circuit, 43 crystal oscillation Child, 44 drive circuit, 45 LCD drive circuit, 5 0 RF section, 51 LNA, 52 mixer, 53 VCO, 54 PLL circuit, 55 IF amplifier, 56 IF filter, 57 ADC (A / D converter), 60 baseband section, 61 DSP, 62 CPU, 63 SRAM, 64 RTC, 65 crystal oscillation circuit (TCXO) with temperature compensation circuit, 66 flash memory, 80 time display device, 90 power supply device, 220 protective film, 221 transparent electrode, 222 p-type semiconductor, 223 i-type semiconductor, 224 n-type semiconductor 225 Metal electrode, 226 Plastic film substrate, 227 Protective film, 228 Amorphous silicon

Claims (10)

A wrist device having a function of receiving a predetermined radio wave using power generated by photovoltaic power generation as a power source,
A solar cell that performs the photovoltaic generation;
A secondary battery for accumulating charges generated by the photovoltaic power generation of the solar cell;
An antenna that receives the radio wave that has passed through the solar cell;
A wrist device comprising: a connection control unit that performs control to electrically connect or disconnect between the electrode of the solar cell and the electrode of the secondary battery when receiving the radio wave. In claim 1,
The connection control unit
A wrist device that performs control so as to electrically disconnect between the electrode of the solar cell and the electrode of the secondary battery from the start to the end of reception of the radio wave. In claim 1,
A reception level detection unit for detecting the reception level of the radio wave,
The connection control unit
A wrist device that performs the control based on a detection result of the reception level at the start of reception of the radio wave. In claim 3,
The connection control unit
A wrist device that performs the control based on a detection result of the reception level at a predetermined timing even during reception of the radio wave. In claim 3 or 4,
The connection control unit
When the detected reception level is lower than a predetermined value, the wrist device is controlled to electrically disconnect between the electrode of the solar cell and the electrode of the secondary battery. In any of claims 1 or 3 to 5,
Including an illuminance detector that detects the illuminance of light incident on the solar cell;
The connection control unit
A wrist device that performs the control based on a detection result of the illuminance at the start of reception of the radio wave. In claim 6,
The connection control unit
A wrist device that performs the control based on the detection result of the illuminance at a predetermined timing even during reception of the radio wave. In claim 6 or 7,
The connection control unit
When the detected illuminance is higher than a predetermined value, the wrist device is controlled to electrically disconnect between the electrode of the solar cell and the electrode of the secondary battery. In any one of Claims 1 thru | or 8.
The wrist device characterized in that the frequency of the radio wave is a microwave. In any one of Claims 1 thru | or 9,
The radio wave is a satellite signal transmitted from a position information satellite,
A time correction information generating unit that acquires satellite information from the satellite signal received by the antenna and generates time correction information based on the satellite information;
A time information correction unit for correcting the internal time information based on the time correction information;
A time information display unit for displaying the internal time information,
Wrist device that functions as an electronic watch.