JP2017146111A - Display device, control method, program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that performs flexible power saving control corresponding to the necessity and urgency of power saving.SOLUTION: A terminal device 100 comprises a battery 15, a GPS receiver 16, a control unit 17, and a display 110. The control unit 17 obtains a current position with the GPS receiver 16, and displays map information and a route to a destination on a display 110. If duration of a battery 15 is shorter than a required time to the destination, the control unit 17 reduces at least one of the acquisition frequency of the current position by the GPS receiver 16 and the brightness of the display 110.SELECTED DRAWING: Figure 2

Description

  The present invention relates to power saving control during route guidance.

  Conventionally, a technique related to power saving control at the time of route guidance is known. For example, in Patent Document 1, when the road to the next guide point is a straight road having a predetermined distance or more, the route to the point where the guide point needs to be guided is route-guided by the power saving guide mode. Techniques for performing are disclosed.

JP 2014-202490 A

  In Patent Document 1, no consideration is given to the remaining amount of power of the battery, and there is no disclosure or suggestion about performing flexible power saving control according to the necessity and urgency of power saving.

  The present invention has been made to solve the above-described problems, and has as its main object to provide a display device that performs flexible power-saving control according to the necessity and urgency of power-saving. .

  The invention described in the claims includes a battery, an acquisition unit that acquires a current position, a display unit that displays map information and a route to a destination, and a time that the battery has longer than a required time to the destination A control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the acquisition unit is short.

  Further, the invention described in the claims is a control method executed by a display device having a battery and a display unit that displays map information and a route to a destination, and an acquisition step of acquiring a current position; A control step of reducing at least one of the acquisition frequency of the current position and the luminance of the display unit by the acquisition step when the battery has a shorter holding time than the required time to the destination. Features.

  The invention described in the claims is a program executed by a computer of a display device having a battery, map information and a route to a destination, and an acquisition unit for acquiring a current position. The computer functions as a control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the battery life is shorter than the required time to the destination It is characterized by making it.

The front view of a terminal device is shown. The schematic structure of a terminal device is shown. The example of a display of the display at the time of route guidance is shown. (A) shows a table in which the acquisition frequency of the current position and the amount of reduction in display brightness are determined according to the distance to the next guide point. (B) shows a table that defines the frequency of acquisition of the current position and the amount of reduction in the brightness of the display in accordance with the remaining battery power. (A) shows an example of a list screen display. (B) shows an example of a map screen display. It is a flowchart which shows the procedure of power saving control. The structural example of the system which concerns on a modification is shown.

  According to a preferred embodiment of the present invention, the display device includes a battery, an acquisition unit that acquires a current position, a display unit that displays map information and a route to a destination, and a time that the battery has A control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the time required to reach the ground is shorter.

  The display device includes a battery, an acquisition unit, a display unit, and a control unit. The acquisition unit acquires the current position. The display unit displays map information and a route to the destination. The control unit reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the battery life is shorter than the required time to the destination. According to this aspect, the display device reduces at least one of the current position acquisition frequency and the luminance of the display unit when there is a high necessity and urgency of power saving that the battery does not have until it reaches the destination. Thus, the route guidance can be preferably continued.

  In one aspect of the display device, the control unit reduces a reduction amount for reducing at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit based on a distance to a next guide point. Change. In a preferred example, the control unit increases a reduction amount that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit as the distance to the next guide point is longer. . In this way, when the distance to the next guide point is large, the display device has a low necessity for route guidance at the present time, so the acquisition frequency of the current position or the reduction amount of the luminance reduction of the display unit is increased. To do. Thereby, the display device can flexibly execute power saving.

  In another aspect of the display device, the control unit reduces a reduction amount that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit based on a remaining power of the battery. To change. In a preferred example, the control unit increases a reduction amount for reducing at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit as the remaining power of the battery is small. As described above, since the display device is more urgent to perform power saving as the remaining amount of battery power is smaller, the display device increases the acquisition frequency of the current position or the reduction amount of the luminance of the display unit. Thereby, the display device can flexibly execute power saving.

  In another aspect of the display device, the control unit reduces the acquisition frequency of the map information corresponding to the current position when the display unit does not display the map information. According to this aspect, the display device can suitably realize power saving when moving without displaying map information.

  In another aspect of the display device, when the display unit displays the map information, the control unit changes the scale of the map information so that a display area based on the map information is wide, In addition, the display update frequency is lowered. Also according to this aspect, the display device can suitably achieve power saving when moving to display map information.

  In another embodiment of the display device, the display device is portable.

  According to another embodiment of the present invention, a control method executed by a display device having a battery and a display unit that displays map information and a route to a destination, an acquisition step of acquiring a current position; And a control step of reducing at least one of the acquisition frequency of the current position and the luminance of the display unit by the acquisition step when the battery holding time is shorter than the required time to the destination. By executing this control method, the display device has at least the current position acquisition frequency and the brightness of the display unit when there is a high necessity and urgency of power saving that the battery does not have until it reaches the destination. One can be reduced and the route guidance can be preferably continued.

  According to another embodiment of the present invention, a program executed by a computer of a display device having a battery and a display unit that displays map information and a route to a destination, the acquisition unit acquiring a current position And the computer as a control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the battery life is shorter than the required time to the destination. Make it work. When the computer executes this program and there is a high need for power saving and urgency that the battery does not have until it reaches the destination, the computer acquires at least one of the current position acquisition frequency and the brightness of the display unit. The route guidance can be suitably continued by reducing. Preferably, the program is stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[overall structure]
FIG. 1 shows a front view of a terminal device 100 which is an example of a display device according to the present invention. The terminal device 100 is a portable terminal that can be carried by a user, and includes a display 110 on which a touch panel 120 is stacked. The terminal device 100 provides route guidance to a designated destination for pedestrians and vehicles.

  FIG. 2 shows a schematic configuration of the terminal device 100. As illustrated in FIG. 2, the terminal device 100 includes an output unit 11, an input unit 12, a storage unit 13, a communication unit 14, a battery 15, a GPS receiver 16, and a control unit 17. The elements of the terminal device 100 are connected to each other via the bus 10 so that necessary information can be transmitted between the elements.

  The output unit 11 includes a display 110 and a speaker 111 that outputs sound, and outputs information for responding to the operation of the user of the terminal device 100 based on the control of the control unit 17. The display 110 is an example of the “display unit” in the present invention. The input unit 12 is an interface that includes a touch panel 120 and accepts input of necessary instructions and information, that is, operations performed by the terminal user to the terminal device 100. For example, the input unit 12 receives an input for specifying a destination, an input for specifying a route search condition, an on / off setting of power saving control described later, and the like. The input unit 12 may include keys, switches, buttons, a voice input device, and the like for inputting various commands and data in addition to or instead of the touch panel 120.

  The storage unit 13 stores a program for controlling the operation of the terminal device 100 and holds information necessary for the operation of the terminal device 100. For example, the storage unit 13 stores various data used for navigation processing such as map data. The map data includes road data represented by links corresponding to roads and nodes corresponding to road connecting portions (intersections), facility information about each facility, and the like. The communication unit 14 transmits / receives data to / from other devices according to a predetermined protocol. For example, the communication unit 14 receives traffic information necessary for route search.

  The battery 15 is a storage battery that can be charged and discharged, and stores electric power necessary for the operation of the terminal device 100. The battery 15 includes a sensor that measures the remaining amount of power and supplies the measurement information to the control unit 17. The GPS receiver 16 receives radio waves carrying downlink data including positioning data from a plurality of GPS satellites, thereby generating information on the current position of the terminal device 100 and transmitting the information to the control unit 17.

  The control unit 17 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and performs various controls on each component in the terminal device 100.

  For example, the control unit 17 receives an input for designating a destination by the input unit 12 and determines a route to the designated destination. Then, the control unit 17 performs route guidance to the destination based on the position information acquired from the GPS receiver 16 and the map data stored in the storage unit 13. In addition, the control unit 17 monitors the remaining amount of power of the battery 15 and controls to reduce energy consumption when it is determined that the amount of power necessary to reach the destination is not charged in the battery 15. I do. The control unit 17 is an example of an “acquiring unit”, a “control unit”, and a “computer” that executes a program.

  Note that the terminal device 100 may include various independent positioning devices such as an acceleration sensor, an angular velocity sensor, and a distance sensor in addition to the components shown in FIG.

  FIG. 3 shows a display example of the display 110 during route guidance. In the example of FIG. 3, the control unit 17 displays a map around the current position on the display 110 based on the current position measured by the GPS receiver 16. In FIG. 3, the control unit 17 displays on the map a current position mark 21 indicating the current position, a route line 22 indicating the route to be traveled, and a branch point on the guide route that changes the travel direction (that is, the next travel direction). , The next guide point) 80 and the guide point image 23 showing the traveling direction at the branch point 80 are displayed. In addition, for example, when the distance between the current position and the next guidance point, the branch point 80, is within a predetermined distance (for example, 1 km, 700 m, 300 m, 50 m, etc.), the control unit 17 The speaker 111 is made to output voice guidance for informing the distance to the branch point 80 and the traveling direction at the branch point 80 (in the diagonally left direction in FIG. 3).

[Power saving control]
Next, power saving control executed by the control unit 17 will be described. Schematically, the control unit 17 determines the frequency of acquisition of the current position by the GPS receiver 16 when the battery 15 estimated time based on the remaining power of the battery 15 is shorter than the expected required time to the destination. By adjusting the brightness of the display 110, power consumption is suppressed. Thereby, the control part 17 suppresses suitably that the electric power remaining of the battery 15 runs out before reaching the destination.

(1) When the adjustment control unit 17 according to the distance to the next guidance point determines that the battery 15 has a shorter holding time than the expected required time to the destination, the distance to the next guidance point is taken into consideration. The frequency at which the current position is acquired by the GPS receiver 16 and the degree to which the brightness of the display 110 is reduced (ie, the reduction amount) are determined.

  FIG. 4A shows a table in which the current position acquisition frequency of the GPS receiver 16 and the luminance reduction amount of the display 110 are determined according to the distance to the next guide point. In FIG. 4A, the item “position acquisition interval” indicates the change in the acquisition interval of the current position of the GPS receiver 16 by the number of seconds, and the item “brightness” indicates the rate of decrease in the luminance of the display 110. Represent.

  As shown in FIG. 4A, the control unit 17 increases the acquisition interval of the current position by the GPS receiver 16 and sets the luminance of the display 110 to be lower as the distance to the next guide point is longer.

  Specifically, when the distance to the next guidance point is “less than 3 km”, the control unit 17 determines that the distance to the next guidance point is relatively close and an accurate current position display is necessary. The acquisition interval of the current position by the GPS receiver 16 is set to the same default value (for example, 1 second) as that in the normal time. On the other hand, as the distance to the next guide point becomes longer as “3 to 30 km”, “31 to 60 km”, “61 to 99 km”, “100 km or more”, the control unit 17 determines the current position of the GPS receiver 16. The acquisition interval is longer than the default value by 1 second, 2 seconds, 3 seconds, and 4 seconds, respectively. As described above, the control unit 17 determines that the longer the distance to the next guide point, the lower the need for route guidance at the present time, and the necessity of displaying the current position with high accuracy is not necessary. The amount of reduction of the current position acquisition frequency by 16 is increased. Thereby, the control part 17 can suppress suitably the power consumption required for the positional information generation by the GPS receiver 16. FIG.

  Similarly, when the distance to the next guidance point is “less than 3 km”, the control unit 17 determines that the distance to the next guidance point is relatively close and the display content on the display 110 needs to be clearly seen. However, the brightness of the display 110 is not reduced. On the other hand, when the distance to the next guide point is 3 km or more, the control unit 17 determines that it is less necessary to immediately clearly see the display content of the display 110, and reduces the brightness of the display 110 by 20%. Let Thereby, the control part 17 can suppress suitably the power consumption required for the display 110 display. Instead of the example of FIG. 4A, the control unit 17 increases the luminance reduction amount so that the luminance reduction amount of the display 110 gradually increases as the distance to the next guide point increases. May be set automatically.

(2) If the adjustment control unit 17 according to the remaining amount of power of the battery determines that the battery 15 has a shorter holding time than the expected required time to the destination, preferably the distance to the next guide point is set. In addition, the remaining power of the battery 15 is further taken into consideration, and the current position acquisition frequency by the GPS receiver 16 and the brightness reduction amount of the display 110 are determined.

  FIG. 4B shows a table that defines the acquisition frequency of the current position of the GPS receiver 16 and the amount of reduction in the brightness of the display 110 according to the remaining power of the battery 15. In FIG. 4B, the item “position acquisition interval” represents the change in the acquisition interval of the current position of the GPS receiver 16 by the number of seconds, and the item “luminance” represents the luminance reduction rate.

  As shown in FIG. 4B, the control unit 17 increases the current position acquisition interval of the GPS receiver 16 and lowers the brightness of the display 110 as the remaining power of the battery 15 decreases.

  Specifically, when the remaining power of the battery 15 is “100 to 80%”, the control unit 17 determines that the urgency of reducing power consumption is low, and sets the acquisition interval of the current position by the GPS receiver 16. Do not increase or decrease. On the other hand, as the remaining power of the battery 15 decreases to “79 to 60%”, “59 to 40%”, “39 to 20%”, and “19 to 0%”, the control unit 17 increases the GPS receiver 16. The acquisition intervals of the current position are increased by “+0.5 seconds”, “+1 seconds”, “+1.5 seconds”, and “+2 seconds”, respectively. As described above, the control unit 17 determines that the urgency of reducing the power consumption is higher as the remaining power of the battery 15 is smaller, and increases the amount of reduction in the acquisition frequency of the current position of the GPS receiver 16. Thereby, the control part 17 can suppress suitably the power consumption required for the positional information generation by the GPS receiver 16. FIG.

  Similarly, when the remaining power of the battery 15 is “100 to 60%”, the control unit 17 gives priority to the visibility of the display 110 and does not increase or decrease the luminance. On the other hand, when the remaining power of the battery 15 is 59% or less, the control unit 17 determines that the urgency for reducing power consumption is relatively high, and reduces the brightness of the display 110 by 20%. Thereby, the control part 17 can suppress suitably the power consumption required for the display 110 display. Instead of the example of FIG. 4B, the control unit 17 increases the luminance reduction step by step so that the luminance reduction amount of the display 110 gradually increases as the remaining power of the battery 15 decreases. May be set.

  When the control unit 17 adjusts the acquisition frequency of the current position of the GPS receiver 16 and the brightness of the display 110 based on both the distance to the next guidance point and the remaining power of the battery 15, FIG. Based on the sum of the values referred to in the respective tables of (B), the acquisition frequency of the current position of the GPS receiver 16 and the brightness of the display 110 are changed.

  For example, consider a case where the distance to the next guide point is “3 to 30 km” and the remaining power of the battery 15 is “59 to 40%”. In this case, the increment of the current position acquisition interval by the GPS receiver 16 referring to the table of FIG. 4A is “+1”, and the current position of the GPS receiver 16 referring to the table of FIG. The increase in the acquisition interval is “+1”. Therefore, the control unit 17 sets a value obtained by adding 2 seconds to the default value (for example, 1 second) of the current position acquisition interval by the GPS receiver 16 as the set value of the current position acquisition interval by the GPS receiver 16. . Similarly, in this case, the luminance reduction amount referring to the table of FIG. 4A is “−20%”, and the luminance reduction amount referring to the table of FIG. 4B is “−20%”. For this reason, the control unit 17 sets a value that is 40% smaller than the current luminance setting value as the luminance setting value of the display 110.

(3) When the vehicle is traveling on a highway (that is, an arterial road such as an expressway), the power saving control control unit 17 during highway traveling changes the power saving control contents according to the display mode of the display 110. Make it. Specifically, the control unit 17 displays a list (also referred to as “list screen display”) of major points (including facilities) scheduled to pass through such as a service area without displaying a map during highway traveling. The contents of the power saving control are made different between the case of the mode and the case of the display mode for displaying the map screen.

  FIG. 5A shows a display example of the display 110 in a case where it is set to display a list screen when traveling on a highway. In FIG. 5 (A), instead of displaying a map, the control unit 17 displays guide images 27 to 29 corresponding to main points to be passed, such as a parking area to be passed or a junction, in accordance with the passing order. . Here, in the guidance images 27 to 29, the names of the corresponding points, the remaining distance until the passage, and the scheduled passage time are displayed, respectively.

  When the control unit 17 is executing the list screen display and determines that the battery 15 has a shorter holding time than the expected required time to the destination, the control unit 17 generates a map screen that is not currently displayed in the background. In addition to reducing the frequency (including stopping the process), the frequency of updating the remaining distance to each point to be displayed on the guide images 27 to 29 and the scheduled passage time is reduced. That is, the control unit 17 suitably suppresses power consumption by reducing the processing frequency in the background regarding a map that is not used for the current display. In addition, the control unit 17 reduces the display update frequency of the display 110 by appropriately reducing the rewriting frequency of the remaining distance to each point to be displayed on the guide images 27 to 29 and the estimated passing time, and appropriately suppresses power consumption. To do.

  FIG. 5B shows a display example of the display 110 when the map screen display is set when traveling on a highway. In FIG. 5B, the control unit 17 displays the current position mark 21, the route line 22 to the destination, the guide point image 23, etc. on the map around the current position, as in the display example of FIG. ing.

  When the controller 17 displays the map screen during highway traveling, the controller 17 reduces the scale of the map displayed on the display 110 when it determines that the battery 15 has a shorter holding time than the expected required time to the destination. Display the wide area of the scale and reduce the display update frequency. As described above, since the control unit 17 displays the map in a wide area, the movement of the current position mark 21 on the map becomes relatively small. Therefore, even if the display update frequency is lowered, the driver feels uncomfortable. Hateful. In this case, the control unit 17 may decrease the display frequency as the distance to the next guidance point is longer or as the remaining power of the battery 15 is smaller. Thereby, the control part 17 can reduce electric power consumption suitably according to the necessity for route guidance.

[Processing flow]
FIG. 6 is a flowchart showing a procedure of power saving control. The control unit 17 executes the process shown in FIG. 6 when the destination is set.

  First, the control unit 17 searches for a route to the set destination, and calculates an estimated required time to the destination on the determined guide route (step S101). For example, the control unit 17 calculates a cost, which is an index of ease of passage through a road or an intersection, with respect to a candidate route to the destination, and calculates a route from the departure point to the destination that satisfies a user-specified condition. Of these, the route with the lowest cost is searched. When calculating the above-described cost, the control unit 17 considers, for example, the length of the corresponding road, the road width, the presence or absence of traffic congestion, and the like. Then, the control unit 17 sets a route with the lowest cost as a guide route, and calculates an expected required time according to the cost of the guide route.

  Next, the control unit 17 determines whether or not the power saving control setting is turned on (step S102). And the control part 17 advances a process to step S103, when the setting of power saving control is set to ON (step S102; Yes). On the other hand, when the setting of power saving control is off (step S102; No), the control unit 17 performs normal control (step S113). That is, in this case, the control unit 17 does not execute the power saving control described in the present embodiment, and acquires the position information while leaving the acquisition position of the current position by the GPS receiver 16 as a default value (for example, 1 second). And the luminance of the display 110 is kept at the set luminance.

  Next, the control unit 17 determines whether or not the battery 15 has a shorter time than the expected required time to the destination (step S103). In this case, for example, the control unit 17 stores in advance a correspondence table between the remaining amount of power of the battery 15 and the remaining time of the battery 15, and refers to the correspondence table, thereby determining the battery from the detected remaining power of the battery 15. Predict 15 hours. At this time, the control unit 17 calculates the amount of charge expected to the destination or / and the power consumption due to the operation of an application (also referred to as “other application”) not related to the application that executes route guidance. In consideration of this, the remaining time of the battery 15 may be predicted. Then, when the control unit 17 determines that the battery 15 has a time remaining longer than the expected required time to the destination (step S103; No), the control unit 17 determines that it is not necessary to perform power saving control and performs normal control. (Step S113).

  On the other hand, when the control unit 17 determines that the battery 15 has a shorter holding time than the expected required time to the destination (step S103; Yes), the acquisition interval of the current position by the GPS receiver 16 is increased (step S104). And the brightness of the display 110 is reduced (step S105). For example, the control unit 17 specifies the distance to the next guidance point and the remaining power of the battery 15, and refers to the tables in FIGS. 4A and 4B, so that the GPS receiver 16 The number of seconds for increasing the current position acquisition interval and the luminance reduction rate are determined. Thereby, the control part 17 can perform the power saving control according to the present condition suitably considering the present route guidance, the necessity of power saving, etc. suitably.

  Next, the control part 17 determines whether it is drive | working the highway (step S106). If the control unit 17 determines that the vehicle is traveling on the highway (step S106; Yes), the process proceeds to step S107. On the other hand, when the control unit 17 determines that the vehicle is not traveling on the highway (step S106; No), the process proceeds to step S112.

  When traveling on the highway, the control unit 17 determines whether to perform list screen display or map screen display (step S107). When the list screen display is performed (step S107; list screen display), the control unit 17 reduces the acquisition frequency in the background of a map screen or the like that is not displayed (step S108). In this case, the control unit 17 may completely stop acquisition in the background such as a map screen that is not displayed. And the control part 17 lowers the update frequency of the remaining distance displayed for every main point to pass through, and passage scheduled time (step S109). Thereby, the control part 17 can reduce suitably the power consumption in the list screen display.

  On the other hand, when performing the map screen display (step S107; map screen display), the control unit 17 changes the scale of the map to be displayed so as to be a wide area display of a predetermined scale (step S110). And the control part 17 reduces the update frequency of the drawing of the display 110 (step S111). In this case, the control unit 17 is preferably configured so that the longer the distance to the next guidance point and the lower the remaining power of the battery 15, as in the tables of FIGS. The display update frequency should be lowered. Thereby, the control part 17 can suppress electric power consumption suitably even if it is during map screen display at the time of highway driving | running | working.

  After executing Step S109, S111, or S113, the control unit 17 determines whether or not the destination has been reached (Step S112). And the control part 17 complete | finishes the process of a flowchart, when it arrives at the destination (step S112; Yes). On the other hand, the control part 17 returns a process to step S102, when it has not arrived at the destination (step S112; No).

  As described above, the terminal device 100 according to the present embodiment includes the battery 15, the GPS receiver 16, the control unit 17, and the display 110. The control unit 17 acquires the current position by the GPS receiver 16 and displays the map information and the route to the destination on the display 110. And the control part 17 reduces the acquisition frequency of the present position by the GPS receiver 16, and the brightness | luminance of the display 110, when the holding time of the battery 15 is shorter than the required time to the destination. According to this aspect, the display device can reduce power consumption and preferably continue route guidance when there is a high need for power saving and urgency that the battery 15 does not have until it reaches the destination. .

[Modification]
Hereinafter, each modification suitable for the above-described embodiment will be described. Each of these modified examples can be applied to the above-described embodiments in any combination.

(Modification 1)
In the flowchart of FIG. 6, the control unit 17 performs both the adjustment of the position information acquisition frequency in step S104 and the luminance adjustment in step S105 as power saving control. Instead of this, the control unit 17 may execute only one of step S104 and step S105. Even in this case, the control unit 17 can suitably reduce the power consumption when the battery 15 has a shorter holding time than the expected required time to the destination.

(Modification 2)
Instead of the terminal device 100, a server device connected via a network may execute the route search.

  FIG. 7 shows a configuration example of a system according to a modification. In the configuration example of FIG. 7, the terminal device 100 is connected to the server device 200 via the network 150. Then, the terminal device 100 receives information necessary for route guidance including the estimated required time to the destination from the server device 200, performs route guidance, and executes steps S102 to S113 in FIG. Also with the configuration of the present modification, the terminal device 100 can suitably execute power saving control as in the embodiment.

DESCRIPTION OF SYMBOLS 10 Bus 11 Output part 12 Input part 13 Storage part 14 Communication part 15 Battery 16 GPS receiver 17 Control part 100 Terminal apparatus 110 Display 120 Touch panel 150 Network 200 Server apparatus

Claims (11)

Battery,
An acquisition unit for acquiring the current position;
A display unit that displays map information and a route to the destination;
A control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the battery has a shorter holding time than the required time to the destination;
A display device comprising:   The control unit changes a reduction amount for reducing at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit based on a distance to a next guide point. Item 1. The display device according to item 1.   The control unit increases a reduction amount for reducing at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit as the distance to the next guide point is longer. The display device according to claim 2.   The said control part changes the reduction amount which reduces at least one of the acquisition frequency of the said present position by the said acquisition part, and the brightness | luminance of the said display part based on the electric power remaining amount of the said battery. The display device according to any one of 1 to 3   The control unit increases a reduction amount for reducing at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit as the remaining amount of power of the battery is small. 4. The display device according to 4.   The said control part reduces the acquisition frequency of the said map information corresponding to the said current position, when the said display part is not displaying the said map information, The any one of Claims 1-5 characterized by the above-mentioned. The display device described.   When the display unit displays the map information, the control unit changes the scale of the map information so that a display area based on the map information is wide, and reduces the display update frequency. The display device according to claim 1, wherein the display device is a display device.   The display device according to claim 1, wherein the display device is portable. A control method executed by a display device having a battery and a display unit that displays map information and a route to a destination,
An acquisition process for acquiring the current position;
A control step of reducing at least one of the acquisition frequency of the current position by the acquisition step and the luminance of the display unit when the battery life is shorter than the required time to the destination;
A control method characterized by comprising: A program executed by a computer of a display device having a battery and a display unit that displays map information and a route to a destination,
An acquisition unit for acquiring the current position;
Causing the computer to function as a control unit that reduces at least one of the acquisition frequency of the current position by the acquisition unit and the luminance of the display unit when the battery life is shorter than the required time to the destination A program characterized by that.   A storage medium storing the program according to claim 10.