JP2009204590A - Portable navigation device - Google Patents

Abstract

[PROBLEMS] To prevent a situation in which route guidance to a destination is interrupted when using route guidance by a portable navigation device that can be carried by a battery.
At the time of route guidance, a CPU checks a remaining battery level (S401) and calculates a battery driving time t (S404, S414). This is compared with the estimated required time T to the destination (S405), and when it is determined that it is not satisfied, various power saving processes (S430) are automatically executed. As the power saving processing, for example, processing is performed such as turning off the screen output except when necessary for route guidance at a branch point, or disabling the use of audio for the purpose of playing music.
[Selection] Figure 4

Description

  The present invention relates to a portable navigation device that performs route guidance based on a route search result and can be carried by a battery.

A portable navigation device that can save power by switching between display and non-display of map information read from the navigation server via communication means according to the estimated required time from the current location to the destination is known. (For example, see Patent Document 1).
JP 2004-101366 A

  However, in the portable communication terminal disclosed in Japanese Patent Application Laid-Open No. 2004-101366 and a navigation system using the same, according to a comparison between an estimated required time from the current location to the destination and a predetermined time set in advance by the user. The display / non-display of the map information is switched. In order to set the predetermined time, the user needs to accurately estimate the battery driving time. When the predetermined time set by the user and the actual battery driveable time are different, an event occurs in which the battery is depleted and the route guidance is forcibly terminated before the route guidance is completed. Therefore, when the accuracy of estimating the battery driving time is low due to the fact that the user has little experience using the portable navigation device, there is a problem that the above-described event that affects convenience is likely to occur.

(1) A portable navigation device driven by a battery according to a first aspect of the present invention comprises route guidance means for guiding a user by a route guidance screen on a branch road on a route from the current location to the destination, and from the current location to the destination. Based on the required time calculating means for calculating the required time, the detecting means for detecting the remaining capacity of the battery, and the remaining capacity of the battery detected by the detecting means, whether the route guiding means can be driven by the required time and the battery. And a power saving processing means for starting a power saving process for suppressing power consumption of the battery when it is determined by the determining means that the route guiding means cannot be driven by the battery for the required time. It is characterized by that.
(2) In the portable navigation device according to claim 1, when the power saving process is activated by the power saving processing means, the route guidance screen is not displayed and the distance to the branch point is The display of the route guidance screen is resumed when approaching a predetermined value, and the route guidance screen is hidden again when passing through the branch point.
(3) According to the invention of claim 3, in the portable navigation device according to claim 1 or 2, the processing means for performing various processes other than the route guidance processing by the route guidance means, and the power saving processing means It is further characterized by further comprising an interruption / prohibition means for interrupting or prohibiting processes other than the route guidance process by the processing means when the processing is activated.
(4) In the portable navigation device according to any one of claims 1 to 3, when the remaining battery capacity detected by the detection unit is equal to or less than a predetermined value, the route guidance screen is provided. Storage control means for storing the route guidance screen data displayed in the storage medium, and resumption means for calling the route guidance screen data stored in the storage medium in accordance with a user instruction and resuming display of the route guidance screen. It is characterized by that.
(5) According to a fifth aspect of the present invention, in the portable navigation device according to the fourth aspect, the portable navigation device further comprises a transfer means for transferring the route guidance screen data stored in the storage medium to another device.
(6) According to a sixth aspect of the present invention, in the portable navigation device according to the fifth aspect, the transfer means is a display control means for displaying a guidance screen that prompts the user to transfer the route guidance screen data to another device. Portable navigation characterized by further comprising command means for the user to instruct data transfer, and transferring the route guidance screen data to another device when a data transfer command is output from the command means after display of the guidance screen machine.

  ADVANTAGE OF THE INVENTION According to this invention, the situation where the battery remaining charge of a portable navigation apparatus falls and the route guidance to the destination is interrupted can be prevented beforehand.

--- First embodiment ---
An embodiment in which a portable navigation device according to the present invention is applied to a portable navigation device (PND) will be described with reference to FIGS. The PND is a navigation device that is carried when a pedestrian moves to a destination. FIG. 1 is a schematic diagram relating to the present embodiment.

  The PND 100 is a navigation device carried by a pedestrian, and the pedestrian moves to a destination according to route guidance by the PND 100. Therefore, the pedestrian is a user of PND100. The PND 100 includes an antenna that detects a GPS signal from a GPS (Global Positioning System) artificial satellite necessary for detecting the current location.

  FIG. 2 is a block diagram showing the hardware configuration of the PND 100. As shown in FIG. In the CPU 110 of the PND 100, signals between the GPS sensor 121, the gyro sensor 122, and the user input device 130 are input / output. The GPS sensor 121 and the gyro sensor 122 are sensors for detecting the current location of the PND 100, and the user input device 130 provides a user interface such as a touch panel or a push button switch around the panel.

  The CPU 110 is a processor that controls the entire PND 100, and the CPU 110 and its peripheral circuits are connected to each other via a bus. The peripheral circuit includes a data memory / work memory 111, a program memory 112, a display module 140, an audio unit 150 for reproducing a medium on which music is recorded, a storage device 160, an external transfer interface 170, a battery control unit 180, and the like. The data memory / work memory 111 is used as a work area for the CPU 110 for control, and the program memory 112 stores a control program for the CPU 110. The audio unit 150 is a player device that performs media playback or the like on which music is recorded. The audio unit 150 may be configured by a broadcast receiver and decoder for receiving radio broadcasts, a communication interface module and decoder for receiving download data from various media servers, and a combination of these devices. You may comprise so that the one part function of those apparatuses may be performed with a program (software).

  The display module 140 includes a graphic controller 141, an image memory 142, a display panel 143, and the like. The graphic controller 141 stores image data such as characters and graphics output from the CPU 110 in the image memory 142 and performs control for displaying the image on the display panel 143.

  The storage device 160 is a storage device that stores information such as road map data and POI (Point of Interest or various facilities) information used for navigation processing. For example, a flash memory is used. In addition to the flash memory, the storage device 180 may be a hard disk, a CD-ROM, a DVD, or other recording medium that stores road map data.

  The road map data is information relating to the map, and includes map display data, route search data, guidance data (intersection name / road name / direction name / direction guide facility information, etc.) and the like. The map display data is data for displaying the road and the background of the road map. The route search data is data including branch information that is not directly related to the road shape, and is mainly used when calculating (route search) a recommended route. The guidance data is data including intersection names and the like, and is used when the user is guided based on the calculated recommended route.

  The external transfer interface 170 is used when the PND 100 performs data transfer to another electronic device. As a communication method for data transfer, Bluetooth (registered trademark), infrared communication, or the like is used. When such wireless communication is used, the external transfer interface 170 includes an antenna for transmitting and receiving data, an RF (Radio Frequency) circuit (not shown), and the like.

  The battery control unit 180 monitors the capacity of the battery 185. Therefore, the CPU 110 can know the remaining amount of the battery 185 through a notification from the battery control unit 180 or an inquiry to the battery control unit 180. It is difficult for the user to accurately estimate the battery driving time based on the remaining amount of the battery 185. Therefore, a conversion table for the CPU to calculate the battery driving time based on the remaining amount of the battery 185 is set in advance in the program memory 112 or the like. Note that the calculation result of the battery driving time based on the remaining amount of the battery 185 is different between the case where the user of the PND 100 uses the audio unit 150 and the case where the user does not use the audio unit 150. Conversion table is required.

  Next, the route guidance process of the PND 100 will be described with reference to the flowchart of FIG. In general, the PND is also assumed to be used as an in-vehicle navigation device while receiving power supply from an automobile. In step S310, a selection menu screen for vehicle guidance / pedestrian guidance is displayed. When vehicle guidance is selected by user input, a mode (vehicle mode) used for vehicle guidance is set in step S311. Subsequently, in step S312, route guidance is performed using road data excluding pedestrian roads and bicycle roads.

  In step S310, when pedestrian guidance is selected by user input, a mode (pedestrian mode) used for the purpose of pedestrian guidance is set in step 321. Subsequently, in step 322, the route guidance using the road data on which the pedestrian can walk is made possible. Although the road data of the vehicle navigation device can be used, it is preferable to release the one-way restriction or the vehicle passage time restriction defined in the road data.

  When the process of step 312 or step 322 is completed, the moving speed is automatically set according to the above-described mode in step S313. For example, the vehicle mode is 40 km / h, and the pedestrian mode is 4 km / h. You may comprise so that a user may set a moving speed. In step S314, the current location is detected by the sensors described above. In step S315, the destination is set by user input. In step S316, the route search process to the destination and the estimated required time T to reach the destination are calculated. It is also possible to specify a waypoint on the route to the destination.

  In step S317, a process for determining whether power is supplied from the vehicle battery is performed. As described above, when the PND 100 is used while receiving power supply from the in-vehicle battery, an affirmative determination is made in step S317 and route guidance is executed in step S318. When arriving at the destination in step S319, the route guidance is finished and this processing flow is finished.

  On the other hand, when the PND 100 is used while receiving power supply from the internal battery, a negative determination is made in step S317 described above, and the process proceeds to step S400. In step S400, a battery-driven subroutine process is executed, and when the subroutine process is completed, this process flow is also terminated.

  Next, a battery-driven subroutine process corresponding to step S400 of FIG. 3 will be described with reference to the flowchart of FIG. In this subroutine processing, first, in step S401, an inquiry is made to the battery control unit 180 to check the remaining battery level. Next, in step S402, it is confirmed whether the operation mode for battery-driven use at that time is the normal mode or the audio use mode, and the process proceeds to the next processing step depending on the confirmation result. . For example, when the confirmation result is the normal mode, the transition setting to the processing step corresponding to the normal mode is performed in step S403, and the battery driving time t calculation process in the normal mode is executed in step S404.

  If it is determined in step S402 that the audio use mode is selected, the operation mode is set to the audio use mode in step S413, and the battery driving time t in the audio use mode is calculated in step S414.

  When the process of step S404 or step S414 is completed, it is determined in step S405 whether or not the battery driving time t is equal to or longer than the estimated required time T until reaching the destination. If it is determined in step S405 that t is equal to or greater than T, the process proceeds to step S406, and a battery check cycle timer for periodically executing the battery remaining amount check is started. In step S407, route guidance is executed.

  If it is determined in step S405 that t is smaller than T, a power saving mode subroutine process is executed in step S430.

  If the event occurrence in step S408 is detected during the route guidance executed in step S407, the process proceeds to the next processing step according to the detection result. For example, if the detection result is an event of destination arrival, it is set in step S409 that the event is destination arrival, route guidance is terminated in step S410, and this subroutine processing flow is terminated.

  If the detection result of event occurrence in step S408 is an event of expiration of the battery confirmation cycle timer activated in step S406, it is set in step S469 that the event is expiration of the battery confirmation cycle timer, and is described above. It returns to the battery remaining amount confirmation process of step S401.

  When the operation mode of the battery is the normal mode, use of audio may be started by user input during route guidance. Alternatively, when the battery operation mode is the audio use mode, the use of audio may be stopped by user input during route guidance. Such an event is defined as an audio use setting change event during route guidance. Since changing the audio use setting leads to a change in the battery operation mode, the battery driving time t needs to be recalculated. Therefore, this subroutine processing flow also takes into account the occurrence of an audio use setting change event. That is, if the event occurrence detection result in step S408 is an event for changing the audio usage setting, it is set in step S479 that the event is an audio usage setting change, and the process returns to the battery remaining amount confirmation process in step S401. .

  If the detection result of event occurrence in step S408 is an event of departure from the guidance route, it is set in step S489 that the event is departure from the guidance route, and the route is searched again in step S490 and the destination route is reached. The required time T is recalculated and estimated, and the process returns to the battery remaining amount confirmation process in step S401.

  The calculation of the battery driving time t in step S404 or step S414 is performed by a table lookup method. That is, a conversion table in which the remaining battery level detected in step S401 is associated with the battery driving time is set in advance in the program memory 112 of the PND 100 in FIG. 2, for example, and the detected remaining battery level is set as the battery driving time. Convert. It may also occur when the calculated battery driving time t is longer than the actual battery driving time. Therefore, the remaining amount of the battery may be depleted before reaching the destination due to the balance between the estimated required time T to reach the destination and the actual required time. In such a case, as a detection result of the event occurrence in step S408, it is set in step S499 that the event is low in battery power, and a subroutine process of saving processing is executed in step S500. Note that the event that the remaining battery level is low in step S499 is based on the capacity monitoring of the battery 185 by the battery control unit 180 in FIG. It is preferable to use the remaining battery level obtained by making an inquiry.

  Details of the power saving process in step S430 and the save process in step S500 in FIG. 4 will be described with reference to FIGS. In FIG. 5, in step S431A, the PND 100 is shifted to the power saving mode and a screen display for notifying the user of the fact is output.

  When the process proceeds to step S435A, the screen output is turned off to save power. If the occurrence of an event in step S436A is detected during route guidance when the screen output is off, the process proceeds to the next processing step according to the detection result. For example, if the detection result is an event of arrival at the destination, it is set in step S409A that the event is arrival at the destination, and this subroutine processing flow ends.

  If the detection result of the event occurrence in step S436A is approaching a branch point such as an intersection (for example, within 50 meters), it is determined in step S437A that the event is approaching a branch point such as an intersection (for example, within 50 meters). In step S438A, the screen output is turned on, and route guidance with guidance is performed. When an event of branch point passing occurs in step S439A, the screen output is turned off again in step S435A. In step S436A, when a point of 50 meters is reached to a branch point such as an intersection, an event of approaching a branch point is generated. However, the value may be variably set in advance by user input. .

  If the event occurrence detection result in step S436A is a deviation from the guidance route, it is set in step S457A that the event is a departure from the guidance route, and the route search process to the destination is performed again in step S458A. Execute. When the processing in step S458A is completed, the screen output is turned off in step S435A.

  If the detection result of the event occurrence in step S436A is that the remaining battery level is very low, it is set in step S499A that the event is low in battery level, and a subroutine process of saving processing is executed in step S500A. When the subroutine processing in step S500A is completed, this subroutine processing flow is terminated.

  Next, a subroutine process of the save process corresponding to step S500A of FIG. 5 will be described with reference to the flowchart of FIG. In this subroutine process, first, in step S501A, a screen display for notifying the user that the route guidance is interrupted and the save process is started is output. Next, in step S502A, power supply to the GPS sensor and the gyro sensor is stopped.

  Further, the process proceeds to the next processing step according to the detection result in the event occurrence detection process in step S508A. For example, if the detection result is an event of arrival at the destination (however, since the power supply to the GPS sensor or the gyro sensor is stopped, an event is generated by user input), the event arrives at the destination at step S509A. This subroutine processing flow is terminated. If the event occurrence detection result in step S508A is an event of power exhaustion, in step S519A, it is set that the event is power exhaustion, and a screen display for notifying the user of power exhaustion is output in step S520A. Then, this subroutine processing flow ends. If the detection result of event occurrence in step S508A is an event called a guide map call, in step S529A, it is set that the event is a guide map call, and the process proceeds to step S530A. In step S503A, a guide map when the route guidance is interrupted in step S501A is displayed for a predetermined time. In order to prevent the user from forgetting to turn off the screen after the screen output is displayed, the screen output is turned off as shown in step S507A when a predetermined time has elapsed from the output display.

The PND 100 of the present embodiment has the following operational effects.
(1) When the user uses the PND 100 by battery driving, the CPU 110 calculates the battery driving time and determines whether or not this driving time is longer than the required time to the destination. Thereby, it is not necessary to compare and determine the battery driving time estimated by the user and the required time to the destination, and the route guidance is forcibly terminated before the destination because the battery driving time estimated by the user is short. Can be prevented.
(2) When it is determined that the battery driving time of the PND 100 is less than the required time to the destination, the CPU 110 automatically drives the PND 100 in the power saving mode. As a result, the battery driving time can be extended as compared with the normal usage mode while performing the minimum route guidance.
(3) When the power saving mode is automatically set by the CPU 110, the screen output is turned off, the screen output is automatically turned on when approaching the branching point, and the screen is automatically reopened when passing through the branching point. It was configured to turn off the output. As a result, even when there is no allowance for battery driving time, the user himself / herself does not need to perform manual operation for turning on / off the screen output for the purpose of power saving, and uses the battery-driven PND 100 attached to a motorcycle. The convenience in the case where manual operation of the PND 100 becomes impossible for two-wheeled vehicle operation is enhanced.

--- Second embodiment ---
Next, a second embodiment of the PND 100 according to the present invention will be described with reference to the flowchart of FIG. In the following description, the same components as those in the first embodiment are denoted by the same reference symbols except for the end of the reference symbols, and differences will be mainly described. Points that are not particularly described are the same as those in the first embodiment. In the present embodiment, as apparent from a comparison between FIG. 7 and FIG. 5, the processing executed due to the power saving mode is different from that of the first embodiment. That is, in FIG. 7, when the mode is shifted to the power saving mode in step S431B, the audio unusable setting is made in step S432B, thereby preventing the power consumption accompanying the audio use.

  When the event occurrence in step S436B is detected during the route guidance to be continued thereafter, the process proceeds to the next processing step according to the detection result. Each event of step S409B, step S457B, and step S499B shown in FIG. 7 is the same as step S409A, step S457A, and step S499A corresponding to FIG.

  The PND 100 according to the present embodiment has the same operational effects as the first embodiment.

--- Third embodiment ---
A third embodiment of the PND 100 according to the present invention will be described with reference to the flowcharts of FIGS. In the following description, the same components as those in the first and second embodiments are denoted by the same reference symbols except for the end of the reference symbols, and differences will be mainly described. Points that are not particularly described are the same as those in the first or second embodiment. In the present embodiment, processing to be executed mainly due to the power saving setting is different from the first and second embodiments. That is, in FIG. 8, when the mode is shifted to the power saving mode in step S431C, the subroutine process of the saving process in step S500C is executed immediately after that.

  With reference to the flowchart of FIG. 9, the subroutine process of the saving process corresponding to step S500C of FIG. 8 will be described. In this subroutine process, first, in step S501CX, a screen display for notifying the user that the route guidance is interrupted and the saving process is started is output. Next, in step S502CX, power supply to the GPS sensor and the gyro sensor is stopped. In step S503CX, the image data of the guide map on the route guidance display screen and the text data related to the route guidance are stored in the data memory / work memory 111. At this time, only the image data of the guide map may be stored, or the image data of a plurality of types of guide maps including an enlarged view of the branch point may be stored. After saving the data, the screen output is turned off in step S507CX.

  Further, when the event occurrence in step S508CX is detected, the process proceeds to the next processing step depending on the detection result. If the detection result is an event of arrival at the destination (however, an event occurs due to user input because power supply to the GPS sensor or gyro sensor is stopped), or an event of power depletion, Processing similar to the processing in the flowchart of FIG. 6 described in the first embodiment is executed. However, after executing these processes, the image data of the guide map saved in step 503CX and the text data related to route guidance are deleted in step S510CX, and this subroutine process is terminated. If the event occurrence detection result in step S508CX is a guide map call event, in step S529CX, the user calls from the guide map image data or the route guidance text data saved in step 503CX. The desired data is selected and output and displayed on the screen for a predetermined time in step S530CX. In order to prevent the user from forgetting to turn off the screen after the screen output is displayed, the screen output is turned off as shown in step S507CX after a predetermined time has elapsed from the output display.

  The PND 100 according to the present embodiment has the same operational effects as the first embodiment. In addition, when the mode is automatically shifted to the power saving mode, the CPU 110 turns off the screen output, and when the user confirms the route, the image data of the saved guide map and the text data related to the route guidance are recalled and displayed. Configured to do. As a result, if the user knows the current position, the user can select an enlarged view / wide area view, text display, etc. as necessary, which is convenient in terms of route selection at a confusing branch point. improves.

--- Fourth embodiment ---
A fourth embodiment of the PND 100 according to the present invention will be described with reference to the flowchart of FIG. In the following description, the same components as those in the third embodiment are denoted by the same reference symbols except for the end of the reference symbols, and differences will be mainly described. Points that are not particularly described are the same as those in the third embodiment. In the present embodiment, the handling of saved data in the save process is mainly different from that in the third embodiment. That is, in FIG. 10, when image data of a guide map and text data related to route guidance are stored in step S503CY, a transfer process of the stored data to an external device is executed.

  In step S504CY, a determination process is performed as to whether or not the stored data is to be transferred to an external device. If it is determined that the data is to be transferred externally, in step S505CY, an external transfer destination device is selected and the PND 100 is connected to the selected external transfer destination device. Note that the connection method may be based on a wired connection, but considering the usage mode of the PND 100, it is preferable that the connection method is mainly based on a wireless connection. As a specific wireless connection method, for example, Bluetooth (registered trademark) or infrared communication can be considered, but other methods may be used. Further, the external transfer destination device candidate may be a device registered in advance by the user in the PND 100, or even if the user inputs information about the external transfer destination device in the process of step S505CY. good. Furthermore, when infrared communication is used as the wireless connection method, the external transfer destination device selection process is executed simply by bringing the external transfer destination device closer to the PND 100. As the external transfer device, for example, an information terminal normally carried by a user who is out, such as a mobile phone, a PDA, a portable PC (personal computer), or a portable game machine, is preferable, but other communication devices may be used. . When an external transfer destination device is selected, external transfer of stored data is executed in step S506CY.

  The PND 100 of the present embodiment has the same operational effects as the first to third embodiments. In addition, even if the power of the PND 100 is depleted before the user reaches the destination, the stored data external transfer processing has been executed before that, so refer to the guide map etc. by the external transfer destination device Can do. Thereby, even when there is no margin in the battery driving time, the reliability is improved in that the minimum information regarding the route to the destination is ensured.

---- Modification ---
Each embodiment mentioned above may be combined, respectively. For example, in the PND 100, the first embodiment and the second embodiment are simultaneously implemented as a power saving process, and if the power of the PND 100 is still exhausted before the user reaches the destination, the third embodiment It is possible to combine the embodiment and the fourth embodiment as a form of saving process at the same time. FIG. 11 and FIG. 12 show the power saving process and the subroutine process of saving process in that case. In FIG. 11 and FIG. 12, the same components as those in the first to fourth embodiments are denoted by the same reference numerals except the end of the reference symbols. Since the processing contents in each step have been described above, description thereof will be omitted.

  In the above-described saving process (FIGS. 6, 9, 10, and 12), guide map output display for a predetermined time is executed in step S530 (A, CX, CY). In the preceding stage, power may be supplied to the GPS sensor and gyro sensor temporarily stopped in step S502 (A, CX, CY) in accordance with the user's instruction. Thereby, in step S530 (A, CX, CY), a guide map in which the current location of the PND 100 is also displayed on the guide map saved in step S503 (A, CX, CY) may be created. Similarly, a guide map that also displays the current location may be created when the guide map is displayed for a predetermined time (step S448E) in the power saving process shown in FIG.

  Furthermore, as long as the characteristic functions of the present invention are not impaired, the present invention is not limited to the device configurations in the above-described embodiment and its modifications.

  In the above-described embodiment and its modifications, for example, the detection unit corresponds to the battery control unit 180, the processing unit corresponds to the audio unit 150, and the command unit corresponds to the user input device 130. The transfer means is realized by an external transfer interface 170, the CPU 110, and a program executed by the program memory 112. The route guidance unit, the storage control unit, the resumption unit, and the display control unit are realized by the display module 140, the CPU 110, and a program executed by the program memory 112. The required time calculation means, determination means, power saving processing means, and interruption / prohibition means are realized by the CPU 110 and a program executed by the program memory 112.

  The above description is merely an example, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiment and the items described in the claims.

1 is a conceptual diagram of an embodiment in which a portable navigation device according to the present invention is applied to a personal navigation device (PND); It is a block diagram showing the hardware constitutions of the personal navigation device (PND) by the 1st Embodiment of this invention. It is a flowchart showing the route guidance process of the personal navigation device (PND) by the 1st Embodiment of this invention. FIG. 4 is a flowchart showing a subroutine process using battery driving described in the flowchart of FIG. 3 in the first embodiment of the present invention. 5 is a flowchart showing a power saving utilization subroutine process described in the flowchart of FIG. 4 in the first embodiment of the present invention. 6 is a flowchart illustrating a subroutine process of a save process described in the flowchart of FIG. 5 in the first embodiment of the present invention. FIG. 5 is a flowchart showing a power-saving use subroutine process described in the flowchart of FIG. 4 in the second embodiment of the present invention. 5 is a flowchart showing a power saving utilization subroutine process described in the flowchart of FIG. 4 in the third and fourth embodiments of the present invention. FIG. 9 is a flowchart showing a subroutine process of a save process described in the flowchart of FIG. 8 in the third embodiment of the present invention. FIG. 9 is a flowchart showing a subroutine process of a save process described in the flowchart of FIG. 8 in the fourth embodiment of the present invention. FIG. 5 is a flowchart showing a power saving use subroutine process described in the flowchart of FIG. 4 in an embodiment in which the first to fourth embodiments of the present invention are combined. FIG. 12 is a flowchart showing a subroutine process of a saving process described in the flowchart of FIG. 11 in an embodiment in which the first to fourth embodiments of the present invention are combined.

Explanation of symbols

100 Personal Navigation Device (PND)
110 CPU
111 Data Memory / Work Memory 112 Program Memory 121 GPS Sensor 122 Gyro Sensor 130 User Input Device 140 Display Module 141 Graphic Controller 142 Image Memory 143 Display Panel 150 Audio Unit 160 Storage Device 170 External Transfer Interface 180 Battery Control Unit 185 Battery

Claims (6)

In portable navigation equipment driven by batteries,
Route guidance means for guiding the user through a route guidance screen on a branch road from the current location to the destination;
A required time calculating means for calculating a required time from the current location to the destination;
Detecting means for detecting the remaining capacity of the battery;
Determination means for determining whether the route guidance means can be driven by the battery for the required time based on the remaining capacity of the battery detected by the detection means;
A power-saving processing unit that activates a power-saving process for suppressing power consumption of the battery when the determination unit determines that the route guidance unit cannot be driven by the battery for the required time. Features portable navigation equipment. The portable navigation device according to claim 1, wherein
When power saving processing is started by the power saving processing means, the route guidance screen is hidden, and when the distance to the branch point approaches a predetermined value, the display of the route guidance screen is resumed, A portable navigation device, wherein the route guidance screen is hidden again when passing through a branch point. The portable navigation device according to claim 1 or 2,
Processing means for performing various processes other than the route guidance processing by the route guidance means;
A portable navigation device further comprising: an interruption / prohibition unit that interrupts or prohibits processing other than the route guidance processing by the processing unit when the power saving processing unit is activated by the power saving processing unit . The portable navigation device according to any one of claims 1 to 3,
Storage control means for storing the route guidance screen data displayed on the route guidance screen in a storage medium when the remaining capacity of the battery detected by the detection means falls below a predetermined value;
A portable navigation device comprising: restarting means for calling up the route guidance screen data stored in the storage medium according to a user instruction and restarting display of the route guidance screen. The portable navigation device according to claim 4, wherein
A portable navigation device comprising transfer means for transferring the route guidance screen data stored in the storage medium to another device. The portable navigation device according to claim 5, wherein
The transfer means further includes a display control means for displaying a guidance screen that prompts a user to transfer the route guidance screen data to another device, and a command means for commanding the data transfer by the user. When the data transfer command is output from the command means after the display, the route navigation screen data is transferred to another device.

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