JP2004077147A - Portable terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal device which is equipped with a position measuring function of a GPS or the like, and is capable of extending its operating time by using a battery efficiently. <P>SOLUTION: A main CPU 21 being a power supply control means controls electric energy supplied from the battery 40, and returns an information processing means 20 from a standby state to its normally operating state, synchronously with an input of a 1PPS signal (pulses generated by a period of one second on the basis of a navigation wave from a satellite 1) being a synchronizing signal generated by a CPU 31. When no 1PPS signals are generated, an internal 1PPS signal generated by the CPU 31 on the basis of oscillation by an RTC 35 is used as a synchronizing signal. Moreover, the main CPU 21 controls the electric energy again corresponding to the finish of predetermined processing by the processing means 20, and transfers the processing means 20 into a standby state. The above process is completed within one second, and is repeated at every one second. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a portable terminal device having a function of acquiring information about a current location based on a positioning signal.
[0002]
[Prior art]
A system that can receive positioning signals and recognize the coordinates (latitude, longitude, and altitude) of the receiving position includes, for example, receiving radio waves from a plurality of satellites and transmitting signals between each satellite and a receiver. There is a satellite navigation system that determines a current position by calculating a distance. One of such satellite navigation systems that has been widely put into practical use is a GPS (Global Positioning system).
[0003]
GPS is developed by the United States Department of Defense, and receives coded navigation radio waves output by at least four satellites out of 24 satellites, demodulates the code (C / A code), and outputs a navigation message. Is a satellite navigation system that enables positioning by extracting and analyzing this. The navigation message includes information for calculating coordinates and a satellite clock correction coefficient. The receiver corrects the satellite clock correction coefficient based on the extracted navigation message, calculates the coordinates, calculates the error of the clock built in the receiver, and automatically adjusts the time of the clock.
[0004]
In recent years, small and light-weight devices such as a portable GPS terminal (handy GPS), a mobile phone having a built-in GPS function, and a PDA (Personal Digital Assistants) have also appeared, and the use of the device outdoors has become popular.
[0005]
[Problems to be solved by the invention]
Such a portable terminal device is configured to receive a navigation radio wave transmitted from a satellite at a cycle of 1 millisecond at any time and perform an operation for positioning at an interval of 1 second. By the way, in the outdoor scenes such as mountain climbing, hiking, cycling, etc., while it is inevitable to rely on the battery to secure the power supply, the traveling speed is several kilometers to 10 km per hour, that is, the traveling distance per second is about several meters. It is only. Therefore, the portion of the portable terminal device that performs the GPS function continuously repeats the positioning within the range of the measurement error while always maintaining the operation state. This only consumes power unnecessarily, and as a result, shortens the driving time of the battery. In particular, in a case such as winter mountain climbing where position confirmation by GPS is a lifeline, the driving time is further shortened due to the influence of a decrease in battery characteristics due to low temperature, but this requires the preparation of many spare batteries. Because it means sex, inconvenience is further increased. The same applies to cases such as long-term adventure travel. In addition, since the length of driving time is generally one of the functions desired by the user for a portable device, it is a great selling point. In addition, considering the recent trend of multifunctional portable terminal devices, it is important to reduce the amount of power consumed by the GPS function that always consumes power in order to effectively use other functions.
[0006]
Therefore, the present invention has been made in view of such circumstances, and a portable terminal device having a positioning function such as GPS capable of extending the driving time by efficiently using a battery is provided. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a portable terminal device according to a first aspect of the present invention includes a driving power source comprising a battery, positioning means for receiving navigation radio waves transmitted from a satellite and acquiring coordinate information of a current position, and Information processing means for processing the coordinate information acquired by the means to create image information; display means for displaying the image information created by the information processing means; and timing for controlling power supply to the information processing means. A synchronizing signal generating means for generating a synchronizing signal for measuring a constant period, and a power control means for controlling power supply from the driving power supply to the information processing means, the power control means, The operation state of the information processing means is returned from the standby state to the normal operation state at predetermined time intervals in synchronization with a synchronization signal. Therefore, since the amount of power consumed by the information processing means can be controlled periodically, it is possible to repeat the positioning operation with less power consumption than the conventional portable terminal device that always operates in the normal operation state.
[0008]
A portable terminal device according to a second aspect is the portable terminal device according to the first aspect, wherein the power control unit responds to the fact that the information processing unit has finished creating the image information. The operation state of the information processing means is shifted from a normal operation state to a standby state. Therefore, the information processing means can reduce the amount of power consumed when there is no need to perform the processing.
[0009]
A portable terminal device according to a third aspect is the portable terminal device according to the first aspect, wherein the synchronization signal generation unit generates the synchronization signal at the cycle based on the received navigation radio wave. It is characterized by the following. Therefore, by measuring the timing of power supply to the information processing means based on the navigation radio waves, it is possible to periodically control the power consumption.
[0010]
A portable terminal device according to a fourth aspect is the portable terminal device according to the first aspect, wherein the synchronization signal generating means independently generates the synchronization signal in the cycle. Therefore, it is possible to periodically control the power consumption regardless of whether the navigation radio wave is received effectively.
[0011]
A portable terminal device according to a fifth aspect is the portable terminal device according to the first aspect, wherein the synchronization signal generating means transmits a first synchronization signal in the cycle based on the received navigation radio wave. A first synchronizing signal generating means for generating the second synchronizing signal, and a second synchronizing signal generating means for generating the second synchronizing signal independently in the cycle, wherein the first synchronizing signal or the second synchronizing signal is generated. It is characterized by further comprising selecting means for selecting any one of the synchronization signals as the synchronization signal. Therefore, it is possible to periodically control the power consumption regardless of whether the navigation radio wave is received effectively.
[0012]
A portable terminal device according to a sixth aspect is the portable terminal device according to the first aspect, wherein the power supply control unit causes the information processing unit to return from the standby state to the normal operation state, and then waits next. The predetermined time indicating a time interval until the state is returned from the state to the normal operation state is the same as the cycle in which the synchronization signal generating means generates the synchronization signal. Therefore, it is possible to control the power consumption within the same time interval as the period of the synchronization signal.
[0013]
A portable terminal device according to a seventh aspect is the portable terminal device according to the first aspect, wherein the synchronization signal and the coordinate information acquired by the positioning unit are input to the information processing unit. And input delay means for delaying the input of the synchronization signal and inputting the coordinate information. Therefore, the information processing means can be returned to the normal operation state at a timing suitable for processing the coordinate information, so that it is possible to minimize wasteful power consumption.
[0014]
In addition, a portable terminal device according to claim 8 is the portable terminal device according to claim 1, wherein the portable terminal device acquires information on a current environment under control of power supply by the power control unit. The power supply control means returns the operation state of the measurement means from a standby state to a normal operation state every predetermined time in synchronization with the synchronization signal. It is characterized by. Therefore, since the amount of power consumed by the measuring means can be controlled periodically, the measurement by the measuring means is repeated with less power consumption than the conventional portable terminal device which always operates in the normal operation state. Becomes possible.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. Note that a description will be given by adopting a GPS as a system for performing positioning and adopting a handy GPS as a portable terminal device according to the present invention.
[0016]
First, a brief description of GPS will be given with reference to FIG. 1 which is a schematic diagram showing the entire configuration of GPS. The satellite 1 is equipped with a synchronized atomic clock and transmits a positioning signal (navigation radio wave) to the ground. The operation of the satellite 1 is monitored by the satellite monitoring station 2 and controlled by the satellite control station 3. The handy GPS 10 receives navigation radio waves from the satellite 1 (and at least three other satellites), acquires the latitude, longitude, and altitude of the current location, and can display the current location on a map, and displays the time and temperature of the current location. It is a device that can also display information such as humidity and the like. The handy GPS 10 uses a C / A code that is open to the general public, and its measurement accuracy by independent positioning is about 25 m in the horizontal direction. In addition, the fixed reference station 4 is a reference point on the ground surface whose position coordinates are accurately known, and the handy GPS 10 can be connected to a computer to use its Internet function, or (if built-in, The measurement error can be corrected to about several meters by using the error information provided from the fixed reference station 5 via the Internet 4 by using the PHS function or the like.
[0017]
Subsequently, an external appearance of the handy GPS 10 will be described with reference to FIGS.
[0018]
FIG. 2 is an external view of the handy GPS 10. A display screen 11 as display means for displaying various information, a start / stop button 12 for operating start and stop of a positioning operation and other various measurement operations are arranged on the front of the exterior, and a side surface is provided with: A power button 13 for turning on / off the power, a PC connector 14 for connecting a personal computer, and an audio connector 15 for connecting external speakers and earphones are provided. In addition, an operation button 16 for performing various operations and a built-in speaker (not shown) are provided on the rear side.
[0019]
FIG. 3 is a schematic diagram showing one display mode of the display screen 11. As the display screen 11, an LCD (Liquid Crystal Display) is usually used, but of course, another display such as a plasma display may be used. The display screen 11 includes a current position display section 11a indicating a current position by, for example, an asterisk, and an azimuth display section 11b indicating an azimuth by an arrow or the like on a map on which contour lines and the like can be additionally displayed, and measurement by various sensors described later. The temperature display unit 11c, the latitude / longitude display unit 11d, the time display unit 11e, the humidity display unit 11f, and the altitude display display the information on the environment of the current location, that is, the temperature, the latitude and longitude, the time, the humidity, the altitude, and the atmospheric pressure at the current location. A display unit 11g and an atmospheric pressure display unit 11h are provided. Although the time is not information on the environment of the current location, the time display unit 11e is useful for displaying an accurate time using navigation radio waves. Further, the display mode of the display screen 11 is not limited to this, and may display information other than the above (for example, information that is not information about the current location environment such as a moving speed), or , And information to be displayed on each display screen may be allocated.
[0020]
The handy GPS 10 will be described with reference to FIG. 4 which is a block diagram showing the internal configuration thereof.
[0021]
The main unit of the handy GPS 10 includes an information processing unit 20 that controls the entire apparatus and a GPS module 30 that processes navigation radio waves from the satellite 1. Also, the display screen 11 and the display memory 11 'of the display means of the present apparatus, the battery 40 of the driving power supply, the direction sensor 50b and the temperature sensor 50c which are measurement means for performing measurement for acquiring information on the current environment of the current location. , The humidity sensor 50 f and the atmospheric pressure sensor 50 h, the audio output unit 60, and the operation unit 70 are connected to the information processing unit 20.
[0022]
The information processing unit 20 is an information processing unit that is configured around the main CPU 21 and processes various signals and information and controls each unit of the apparatus. The main CPU 21 operates based on programs and data stored in the memory 22. Things. In particular, it has an effect as a power control means for controlling the amount of power supplied to each section of the apparatus. Although not shown in detail, the main CPU 21 includes an internal clock and a PLL (Phase Lock Loop) like a normal CPU, and outputs a clock signal for synchronizing various signals input / output in the main CPU. The clock to be generated is connected.
[0023]
The GPS module 30 operates as positioning means for analyzing navigation radio waves received from the satellite 1 and acquiring coordinate information of the current position. The GPS module 30 controls the entire GPS module 30 and performs various calculations, and the CPU 31 and a DSP 34 described later. , A RF (Radio Frequency) unit 33 that converts a navigation radio wave received by an antenna 38 into a processable signal, and a DSP (Digital Signal Processor) that performs digital signal processing. ) 34, an RTC (Real Time Clock) 35 which is a 32 kHz oscillator utilizing crystal oscillation, a PLL 36 for generating an internal clock of the CPU 31 based on the clock from the RTC 35, and a data processed by the CPU 31 and the DSP 34. And an output unit 37 composed of a serial to output.
[0024]
The RF unit 33 has a complex function, and specifically operates as an amplifier for amplifying a signal, a down converter for converting a frequency, and an A / D converter for performing A / D conversion. The DSP 34 is a processor configured to perform high-speed digital signal processing under the control of a program stored in a ROM or the like, while giving details of the general internal configuration to another. , To extract the navigation message, that is, to demodulate the coded navigation radio wave. The RTC 35 has a clock function of the handy GPS 10 by oscillating at a frequency of usually 32 kHz obtained using crystal oscillation. That is, when accurate time data is calculated from the navigation message, correction is performed so that the time data generated based on the oscillation of the RTC 35 matches the accurate time data. 1PPS rising at one second intervals, which will be described later, is a signal generated based on oscillation by the RTC 35. The rise timing of 1PPS is corrected so that the delay error of the rise time of the atomic clock mounted on the satellite 1 is minimized. Since the RTC 35 is configured to continue operating even when the power of the handy GPS 10 is off, almost accurate time is always displayed on the time display unit 11e when the power is turned on.
[0025]
The battery 40 is a driving power source such as a dry battery or a rechargeable battery when the handy GPS 10 is carried. The handy GPS 10 can be operated by an external power source such as a household outlet. In addition, there is a type in which a rechargeable battery can be charged by an external power supply. In FIG. 4, not all of the power supply lines are shown for the sake of simplicity. However, similar to the power supply lines for the main CPU 21 and the GPS module 30 shown as an example, each power supply line shown in FIG. The power is supplied to this. Reference numerals 41 and 42 denote FETs (field effect transistors), and each power supply line is led to each part of the device via the FET. The FET increases or decreases the current flowing through the power supply line under the control of the main CPU 21.
[0026]
The audio output unit 60 embodies an audio output function as an example of an additional function of the handy GPS 10. Although its internal configuration is general, it will not be described in detail, but a DSP for processing digital data for audio output sent by the main CPU 21 and a D / A for converting the data processed by the DSP into analog data. A converter is provided, and the analog data is output to an earphone or the like via the audio connector 15.
[0027]
The operation unit 70 includes a start / stop button 12, a power button 13, an operation button 16, and an input interface for inputting a signal transmitted in response to these operations to the main CPU 21 by the user. Things.
[0028]
Hereinafter, the operation of the handy GPS 10 having such an internal configuration will be described with reference to the flowchart shown in FIG.
[0029]
The satellite 1 periodically (1 millisecond cycle) emits a high-frequency analog navigation signal. When the navigation radio wave is received by the antenna 38 (S1), it is first sent to the RF unit 33. The RF unit 33 converts the navigation radio wave into a signal that can be processed by the DSP 34, and firstly amplifies the navigation radio wave, second down-converts the frequency, and thirdly converts it into a digital signal. (S2). The signal that can be processed by the RF unit 33 is sent to the DSP 34. The DSP 34 extracts a navigation message in accordance with a code demodulation program stored in the memory 32, and the orbit data and time data of the satellite 1 included in the extracted navigation message are analyzed by the CPU 31 to determine the latitude, longitude and current position of the current location. An altitude (referred to as coordinate information or GPS data) and a clock error in the handy GPS 10 are calculated (S3). Further, the CPU 31 generates a synchronization signal called a one-second signal (1PPS) synchronized with the cycle data included in the navigation message. 1PPS is a pulse generated in a one-second cycle, and is generally used for time adjustment, a synchronization system between servers, and the like. When the navigation radio wave is received effectively and 1PPS is generated (the CPU 31 determines whether 1PPS is valid / invalid based on whether the navigation radio wave is received effectively) (S4), the CPU 31 turns on the power supply. 1PPS is sent to the main CPU 21 as a signal for controlling the supply (S5, S7).
[0030]
On the other hand, the CPU 31 generates another one-second signal (referred to as an internal 1PPS) based on the internal clock by the RTC 35 and the PLL 36. When the navigation radio wave could not be received (S1) or when 1PPS was not generated effectively due to other circuit problems (S4), the CPU 31 selects the internal 1PPS as a synchronization signal (S6). It is sent to the CPU 21 (S7).
[0031]
That is, the CPU 31 operates based on whether the function as the first synchronization signal generating means for generating 1 PPS, the function as the second synchronization signal generating means for generating the internal 1 PPS, and whether 1 PPS has been generated effectively. Alternatively, it has an operation as a selection means for selecting any one of the internal 1PPS as a synchronization signal.
[0032]
Further, the CPU 31 synchronizes the timing of transmitting (internal) 1PPS to the main CPU 21 with the calculated GPS data according to the program stored in the memory 32, and starts timing by the internal clock. As will be described later, the time is measured only for the time required for the main CPU 21 to receive the 1PPS input and to prepare for processing the GPS data (PLL stabilization time, time for shifting the processing to the standby mode release interrupt vector). Be done.
[0033]
By the way, as shown in FIG. 5, since the operation of the GPS function is configured to be repeated according to a cyclic process, it is understood that the operation state of the main CPU 21 at the time of S7 is the standby mode (standby state). . When the main CPU 21 in the standby mode receives the 1PPS or the internal 1PPS sent from the CPU 31 (because there is no difference between them, the description will be continued assuming that 1PPS has been sent). The PLL is activated, and after elapse of the stabilization time, the processing is shifted to the standby mode release interrupt vector. After that, the main CPU 21 issues a command to the FET 41 to increase the amount of power supplied to the main CPU 21 and prepares for processing of information that will be input later. The FET 41 acts to adjust (increase) the power of the power supply line according to the instruction. When the amount of power supplied from the battery 40 reaches the specified value, the main CPU 21 returns to the normal mode (normal operation state) (S8), and the preparation for processing the GPS data is completed.
[0034]
The operating state of the main CPU 21 indicates the operating state of the clock of the main CPU 21, and corresponds to a change in the amount of power supplied from the battery 40. In the normal mode, the main CPU 21 is in a normal operation state in which arithmetic processing and the like can be performed, and the main CPU 21, all peripheral circuits thereof, and a PLL (not shown) are in an operation state. In the standby mode, the operation of the main CPU 21 and all of its peripheral circuits and the PLL is in a stopped state, so that the power supply amount is small. In fact, the amount of power consumed by the main CPU 21 in the normal mode and the standby mode is, for example, 10 ⁴ There are differences in order. Therefore, when the operation is unnecessary, it is possible to extend the driving time of the battery 40 by setting the main CPU 31 in the standby mode as much as possible to save power consumption. The names of the operation states are various, and the names of the normal mode and the standby mode are not general. However, in the present specification, these names are used in the meaning defined above. Also, the degree of the difference in power consumption between the normal mode and the standby mode varies depending on the CPU used.
[0035]
The CPU 31 starts timing at the timing of transmitting 1 PPS (S7), but the timing is set so that the main CPU 21 measures the time until it returns to the normal mode. When the time reaches this time, the CPU 31 sends the calculated GPS data from the output unit (serial) 37 to the main CPU 21 (S9). That is, the CPU 31 has an operation as input delay means for inputting GPS data with a delay of a predetermined time after inputting 1 PPS. The main CPU 21 that has obtained the GPS data (S10) creates image information by adding the latitude and longitude information included in the GPS data to the map data stored in the memory 22, and displays the created new image information for display. It is sent to the memory 11 '. At the same time, the main CPU 21 rewrites the contents of the display memory 11 'from the image information corresponding to the image currently displayed on the display screen 11 to this new image information (S11). With the rewriting of the display memory 11 ', the current position is indicated by an asterisk on the display screen 11 on the image based on the new image information, that is, as shown in FIG. The displayed image is displayed. It should be noted that the image information is sent to the display memory 11 'and the contents of the display memory 11' are rewritten, whereby the processing relating to GPS by the main CPU 21 ends. The main CPU 21 issues a command to the FET 41 based on the program stored in the memory 22 so as to decrease the amount of power supplied to the main CPU 21 in response to the end of the process related to GPS. The FET 41 reduces the amount of power supplied to the main CPU 21 in accordance with this command, so that the main CPU 21 shifts to the standby mode (S12). The main CPU 21 in the standby mode waits until the next (internal) 1 PPS is transmitted from the GPS module 30. When the next (internal) 1PPS is input (S7), the main CPU 21 returns to the normal mode again to perform data processing. As a result, the processes of S1 to S12 are circulated every second, and the operation state of the main CPU 21 is alternately switched between the normal mode and the standby mode. At this time, the display on the display screen 11 is updated every second.
[0036]
In order to further reduce the amount of power consumed by the handy GPS 10, it is possible to control the amount of power supplied to the direction sensor 50b, the temperature sensor 50C, the humidity sensor 50f, and the atmospheric pressure sensor 50h. Various sensors provided in the ordinary handy GPS always perform measurement while receiving power supply from the battery 40, and transmit acquired measurement data to the main CPU 21. On the other hand, in the handy GPS 10 of the present embodiment, although not shown in FIG. 4, a power supply line is drawn from the battery 40 via the FET to each sensor, and is supplied to each sensor. The amount of power can be controlled. As in the case of power supply control for the main CPU 21, when 1PPS is input, the main CPU 21 controls the FET to increase the amount of power supplied to each sensor, and returns each sensor to the normal mode (measurable state). (S8). When each sensor measures and transmits the acquired measurement data to the main CPU 21 (S10), the main CPU 21 rewrites the display memory 11 'based on the received measurement data (S11). In response to the rewriting of the display memory 11 ', the main CPU 21 controls the FET again to reduce the power of the power supply line and shift each sensor to a standby mode (power supply may be stopped). . Each sensor waits for the input of the next 1 PPS from the GPS module 30 in the standby mode.
[0037]
FIG. 6 visually shows the amount of power consumed by the handy GPS 10 realizing such an operation process in each stage. The horizontal axis represents time, and the vertical axis represents the amount of power consumed by each component of the handy GPS 10 (power consumption). The arrow drawn along the vertical axis indicates the amount of power consumed by the component when the operating state of the component described therein is the normal mode. Specifically, the GPS module 30 consumes power only by a, the information processing unit 20 and various sensors consume power only by ba, and the other parts such as an audio output unit consume power by c-b.
[0038]
First, since the GPS module 30 is always in the normal mode, a constant amount of power (= a) is supplied. In steps S1 to S7 of FIG. 5, power is consumed by the sum of the amount a supplied to the GPS module 30 and the (very small) amount supplied to the information processing unit 20 and various sensors in the standby mode. And the power consumption is approximately a. When (internal) 1PPS is transmitted in S7 (time t1), the power consumption starts to increase with a slight delay, which is due to the time required until the PLL of the main CPU 21 is stabilized (about 1 ms). . Subsequently, in S8, the supply of power to the main CPU 21 and the various sensors rapidly increases to b, and thereafter enters the normal mode stably. When the predetermined operations of the main CPU 21 and the various sensors are completed (S12, t2), the power consumption sharply decreases to almost a, and thereafter, when the power consumption becomes stable, the mode shifts to the standby mode. At this stage, one second has not yet elapsed since 1PPS was input (t1). That is, the next 1PPS has not been received yet. Therefore, while the conventional handy GPS always consumes as much power as b, the handy GPS 10 of the present embodiment effectively uses 1 PPS generated in a one second cycle as a control signal. As a result, power consumption can be reduced.
[0039]
Actually, if the input / output between the GPS module 30 and the main CPU 21 is a 38400 bps serial transfer, the transfer is performed within 100 ms because the GPS data is about several hundred bytes. Even if the measurement operation of various sensors performed in synchronization with the GPS data, the rewriting operation of the display memory 11 ', the stabilization time of the PLL, and the like are considered, the processing performed by the main CPU 21 is completed in 200 to 300 ms. Of these, about 700 ms remains in the standby mode. Therefore, as compared with the conventional handy GPS in which the information processing unit and various sensors are always in the normal mode, the handy GPS 10 of the present embodiment can operate at about 30% of the power consumption, and therefore, is large. Power saving effect can be expected.
[0040]
The configuration for repeatedly switching the operation state of the main CPU 21 and various sensors based on 1PPS has been described above, but the configuration for controlling power supply using 1PPS is not limited to these. For example, when the main CPU 21 has a function of calculating the user's moving speed based on the GPS data and the built-in clock function, the main CPU 21 performs an operation for calculating the moving speed in synchronization with the input of 1PPS. Can be done.
[0041]
【The invention's effect】
As described above, according to the present invention, the operation state of the information processing means is returned from the standby state to the normal operation state at predetermined time intervals based on the synchronization signal generated by the synchronization signal generation means, and By providing a power supply control unit that shifts from the normal operation state to the standby state in response to the termination, the amount of power consumed by the information processing unit can be periodically controlled. Since the amount of supplied power is saved, a portable terminal device capable of extending the operation time of the battery can be provided.
[0042]
Further, according to the present invention, the amount of electric power supplied to the measuring means can be controlled based on the signal generated by the signal generating means. Type terminal device can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of a GPS as an example of a satellite navigation system.
FIG. 2 is an external perspective view of the handy GPS of the embodiment.
FIG. 3 is a schematic diagram showing one display mode of a display screen of the handy GPS according to the present embodiment.
FIG. 4 is a block diagram illustrating an internal configuration of the handy GPS according to the present embodiment.
FIG. 5 is a flowchart showing an operation of the handy GPS of the embodiment.
FIG. 6 is a time chart schematically illustrating a change in power consumption of the handy GPS according to the present embodiment.
[Explanation of symbols]
10 Handy GPS
11 Display screen
20 Information processing unit
21 Main CPU
30 GPS module
31 CPU
33 RF section
34 DSP
35 RTC
36 PLL
40 battery

Claims (8)

A driving power source consisting of a battery,
Positioning means for receiving navigational radio waves transmitted from satellites and acquiring coordinate information of the current location;
Information processing means for processing the coordinate information obtained by the positioning means and creating image information;
Display means for displaying the image information created by the information processing means,
Synchronous signal generating means for generating a synchronous signal for measuring the timing of controlling the power supply to the information processing means at a constant cycle,
Power supply control means for controlling power supply from the drive power supply to the information processing means,
The portable terminal device according to claim 1, wherein the power control unit returns the operation state of the information processing unit from a standby state to a normal operation state at predetermined time intervals in synchronization with the synchronization signal. 2. The power supply control unit changes an operation state of the information processing unit from a normal operation state to a standby state in response to the end of the creation of the image information by the information processing unit. The portable terminal device as described in the above. 2. The portable terminal device according to claim 1, wherein the synchronization signal generation means generates the synchronization signal in the cycle based on the received navigation radio wave. 2. The portable terminal device according to claim 1, wherein the synchronization signal generator independently generates the synchronization signal in the cycle. The synchronizing signal generating means includes a first synchronizing signal generating means for generating a first synchronizing signal in the cycle based on the received navigation radio wave, and a second synchronizing signal generating means for independently generating a second synchronizing signal in the cycle. And a synchronizing signal generating means,
The portable terminal device according to claim 1, further comprising a selection unit that selects one of the first synchronization signal and the second synchronization signal as the synchronization signal. The predetermined time indicating the time interval from when the power control unit returns the information processing unit from the standby state to the normal operation state after the standby state is returned to the normal operation state, the synchronization signal generation unit performs 2. The portable terminal device according to claim 1, wherein the period for generating the synchronization signal is the same as the period. An input delay unit that inputs the synchronization signal and the coordinate information acquired by the positioning unit to the information processing unit, and further includes an input delay unit that delays input of the synchronization signal and inputs the coordinate information. The portable terminal device according to claim 1, wherein: Under the control of the power supply by the power supply control means, further comprising a measurement means for performing measurement for obtaining information on the environment of the current location,
2. The portable terminal device according to claim 1, wherein the power control unit returns the operation state of the measurement unit from a standby state to a normal operation state at every predetermined time in synchronization with the synchronization signal. .

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