JP2003090728A - Map display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the communication cost for acquiring map data. SOLUTION: A control circuit 80 sets a destination, and positions a present location on the basis of operations at a key operating part 60. The map data indicating the present location is acquired by communications from a base station, and the map data is displayed on a liquid crystal display 50. The time intervals for acquiring the map data are shortened as the distance between the present location and the destination is shortened. By this, it is possible to reduce the times for acquiring the map data in comparison with the case of acquiring the map data every time the present location falls outside the range of the displayed map data.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a map display device for displaying a map.

[0002]

2. Description of the Related Art Conventionally, in a navigation system, as disclosed in Japanese Patent Laid-Open No. 2000-249565, a G
There is a method in which the current position is measured by using a PS antenna or the like, and the map data indicating the measured current position is called from the CD-ROM to display the map on the liquid crystal panel.

However, the CD-ROM does not always store the latest map data, and it may not be possible to display the map data reflecting the newly opened road on the liquid crystal panel.

On the other hand, Japanese Patent Laid-Open No. 10-103993
As disclosed in the publication, a navigation system has been proposed in which the latest map data is acquired from a base station by wireless communication and displayed on a liquid crystal panel, instead of calling the map data from a CD-ROM.

In this device, every time the current location deviates from the range of the map data displayed on the liquid crystal panel,
Obtain map data from the base station. Therefore, the latest map data can be continuously provided to the user from the departure place to the destination, and the user can be guided to the destination well.

[0006]

However, in the navigation system, as described above, the map data is acquired from the base station every time the current location deviates from the range of the displayed map data. Therefore, when the user does not need the map data, such as immediately after departure or while traveling on a known route, the map data is acquired.

Therefore, there arises a problem that the timing of acquiring the map data is increased and the communication cost for acquiring the map data is increased.

In view of the above points, it is an object of the present invention to provide a map display device which acquires map data at an appropriate timing.

[0009]

In order to achieve the above-mentioned object, the present invention is, in the invention described in claim 1, an acquisition means (152) for acquiring map data including the present location by wireless communication.
And a map display device for displaying a map based on the acquired map data, in which the distance from the current position to the destination is obtained, and the map data is acquired by the acquisition means according to the distance from the current position to the destination. Is provided with variable means (180, 210, 240, 260) for varying the interval.

As described above, the setting means changes the interval at which the map data is acquired according to the distance from the current position to the destination. Therefore, the map data can be acquired at an appropriate timing, and the number of times the map data is acquired can be reduced when the user does not need the map data, such as immediately after departure or while traveling on a known route. Therefore, it is possible to reduce the communication cost and power consumption for acquiring the map data.

Specifically, as in the invention described in claim 2, the first determination means (130) for determining whether or not the current location is out of the range of the displayed map data and the setting means are set. A second determination means (140) for determining whether or not the designated interval has elapsed, the first determination means determines that the current location is out of the range of the displayed map data, and The acquisition unit may acquire the map data when it is determined by the second determination unit that the interval set by the setting unit has elapsed.

According to the third aspect of the present invention, there is provided a third determining means for determining the moving distance from the time of acquisition of the map data and for determining whether or not the calculated moving distance is equal to or more than a predetermined threshold value. The acquisition means is characterized by acquiring map data when the movement distance is determined to be equal to or greater than a predetermined threshold value by the third determination means.

As a result, if the moving distance is equal to or greater than the predetermined threshold value even at a timing other than the variable interval as described in the first aspect of the invention, the map data is acquired.
The user can be satisfactorily guided to the destination.

The invention according to claim 4 is characterized in that the shorter the distance from the current position to the destination, the shorter the interval for acquiring the map data by the acquisition means.

As a result, the closer the user gets to the destination, the shorter the interval at which the map data is acquired. Therefore, the closer the user gets to the destination, the better the user can be guided.

Further, in the invention according to claim 5, there is provided a display means (50) for displaying and an acquisition means (152) for acquiring the map data indicating the present location by wireless communication, and the acquired map data is acquired. A map display device for displaying a map on a display means based on the first measurement means (160) for measuring the distance from the current position to the destination, and the distance to the destination is equal to or greater than a first threshold value. First determining means (170, 200, 230) for determining whether or not, a means (400) for obtaining a moving distance from the time of acquisition of map data, and whether or not the moving distance is equal to or more than a second threshold value. And second determining means (410, 420, 430, 440) for determining
When the distance to the destination is determined to be equal to or greater than the first threshold value by the determination means and the movement distance is determined to be equal to or greater than the second threshold value by the second determination means, the acquisition means, It is characterized in that the map data is acquired and output to the display means.

Thus, when the distance to the destination is less than the first threshold, acquisition of map data can be prohibited. In addition, since the acquisition of map data can be prohibited when the movement distance is less than the second threshold value, compared to a case where map data is simply acquired each time the current location deviates from the range of map data,
It is possible to reduce the timing of acquiring map data. Therefore, it is possible to reduce the communication cost and the power consumption for acquiring the map data. Here, in the invention according to claim 6, the second threshold is such that the distance from the current position to the destination is shortened. The feature is that it is set so as to become smaller.

As a result, map data can be acquired with a smaller travel distance as the distance from the current location to the destination becomes shorter, so that the user can be guided better as the distance to the destination becomes closer.

The invention according to claim 7 is characterized in that the degree of detail of the map data acquired by the acquisition means increases as the distance from the current position to the destination decreases.

As a result, the closer the user is to the destination, the more detailed the map data is obtained. Therefore, the closer the user is to the destination, the better the user can be guided.

Incidentally, the reference numerals in parentheses of the above-mentioned respective means are examples showing the correspondence with the concrete means described in the respective embodiments described later.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a first embodiment in which a map display device according to the present invention is applied to a mobile phone. FIG. 1 is a block diagram showing an electric circuit configuration of a mobile phone. As shown in FIG. 1, the mobile phone has an antenna 1
0, a wireless communication unit 20, a GPS antenna 30, a GPS receiving unit 40, a liquid crystal display 50, a key operation unit (keypad) 60, a memory 70, and a control circuit 80.

The antenna 10 receives a received signal from a base station using a radio wave as a medium, and transmits a modulated signal to the base station using a radio wave as a medium. The wireless communication unit 20 demodulates the received signal and outputs the demodulated signal. The wireless communication unit 20 also modulates the transmission signal from the control circuit 80 and outputs the modulation signal.

The GPS antenna 30 receives a satellite signal from each artificial satellite using radio waves as a medium, and the GPS receiving section 40 is controlled by the control circuit 80 to control the GPS signal.
Each satellite signal from the antenna 30 is output. Further, the liquid crystal display 50 is controlled by the control circuit 80 to display a map or the like. The key operation unit 60 includes the display key 6
1, each operation key such as a selection key 62.

The memory 70 stores various data such as a computer program of the control circuit 80 and map data.
The control circuit 80 is composed of a microcomputer, and the microcomputer performs various processes such as a call process and a navigation process.

Next, a specific navigation process in the microcomputer of the control circuit 80 will be described with reference to FIG.
This will be described with reference to FIG. 2 and 3 are flowcharts showing the navigation processing.

The microcomputer of the control circuit 80 is
Execution of the computer program is started according to the flowcharts shown in FIGS. First, step 100
In, the operation of the built-in timer is started and the destination is set.

Specifically, the display key 6 of the key operation unit 60
When 1 is pressed, the map data stored in advance is called from the memory 70 and the map data is displayed on the liquid crystal display 50. Here, in order to select a desired point as a destination from the map data, the key operation unit 60
When the selection key 62 is pressed, the desired point in the map data is selected as the destination. At the same time, the latitude and longitude of the destination are extracted from the map data, and the extracted latitude and longitude of the destination are set in the memory 70.

Next, in step 110, it is determined whether or not the current time is a timing required for positioning. Here, after starting the navigation process, the first step 110
Then, since it is determined that the current time is a timing required for positioning, the process proceeds to step 120.

Here, the arrival time required for the satellite signal from each artificial satellite to reach the mobile phone is obtained based on the output signal from the GPS receiving section 40. Then, the distance from each artificial satellite to the mobile phone is obtained based on each arrival time. Along with this, the latitude and longitude of the current location are obtained by trigonometry based on the respective distances and stored in the memory 70.

Further, the positioning timing for obtaining the current position as described above is obtained based on the built-in timer and stored in the memory 70.

Next, it is determined whether or not the current location is out of the range of the map data displayed on the liquid crystal display 50 (step 130). Here, in the first step 130 after starting the navigation process, this step 1
Prior to 30, the map data is not displayed on the liquid crystal display 50, but YES is determined and the process proceeds to step 140.

Then, it is determined whether or not the current time is the timing at which map data acquisition is required. Here, after starting the navigation process, in the first step 140, it is determined that the current time is the timing required to acquire the map data, and the process proceeds to step 150.

Here, the map data is acquired from the base station by wireless communication and the map is displayed on the liquid crystal display 50 based on the map data. Along with this, the acquisition timing for acquiring the map data is obtained based on the built-in timer, and the acquisition timing is stored in the memory 70.

Here, the degree of detail of the map data is 5
1/0000 is adopted. The details of the process of acquiring the map data in step 150 will be described later.

Next, in step 160, the memory 7
The latitude and longitude of the destination are called from 0, and the distance from the current location to the destination is calculated based on the latitude and longitude of the destination and the latitude and longitude of the current location. At the same time, the direction of the destination based on the present location is obtained.

Next, in step 170, it is determined whether or not the distance to the destination is 100 km or more.
When the distance to the destination is 100 km or more, the process proceeds to step 180, and the time interval for acquiring the map data is set to 5 minutes. Furthermore, the detail level of the map data is 500
It is set to 1/00 (step 190).

Next, at step 170, when the distance is less than 100 km, the routine proceeds to step 200, where it is judged whether the distance to the destination is 50 km or more. Here, when the distance to the destination is 50 km or more, the process proceeds to step 210, and the time interval for acquiring the map data is set to 3 minutes. Further, the detail level of the map data is set to 1/25000 (step 22).
0).

Next, at step 200, when the distance to the destination is less than 50 km, the routine proceeds to step 230, where it is determined whether the distance to the destination is 20 km or more. Here, the distance to the destination is 20 km
When it is above, it progresses to step 240 and sets the time interval which acquires map data to 1 minute. Further, the detail level of the map data is set to 1/10000 (step 250).

Next, in step 230, when the distance to the destination is less than 20 km, the process proceeds to step 260. As a result, the time interval for acquiring map data is 3
Set to 0 seconds. Furthermore, the detail level of the map data is 500
It is set to 1/0 (step 270).

Thus, steps 180, 210, 2
One of 40 and 260 sets a time interval for acquiring map data. Also, steps 190, 220, 25
The degree of detail of the map data is set to either 0 or 270.

After that, the routine proceeds to step 110, where the present time is obtained based on the built-in timer, and the previous positioning timing is called from the memory 70. Along with this, it is determined whether or not the current time is a timing that has passed a certain time or more since the previous positioning timing.

Here, when the current time is a timing at which a certain time or more has elapsed from the previous positioning timing, it is determined that the current time is the timing required for positioning, and the process proceeds to step 120. Then, similar to the above, based on each amplified signal from the GPS receiver 40, the current position is measured.

Next, it is determined whether or not the current location is out of the range of the map data displayed on the liquid crystal display 50 (step 130). Then, when the current location is out of the range of the map data, the process proceeds to step 140.

Here, the present time is obtained from the built-in timer, and the acquisition timing of the previous map data is called from the memory 70. Along with this, it is determined whether or not the current time is the timing at which the time interval or more has elapsed since the previous acquisition timing.

Here, when the current time is the timing when the above time interval or more has passed after the previous acquisition timing,
It is determined that the current time is the acquisition timing of map data,
Go to step 150. Therefore, the map data of the setting detail level is acquired from the base station and displayed on the liquid crystal display 50. Then, it progresses to step 160.

Below, in the above-mentioned step 150,
An acquisition process in which the mobile phone acquires map data from the base station and a transmission process in which the base station transmits the map data to the mobile phone will be described with reference to FIGS. 4 and 5.

FIG. 4A is a flowchart showing an acquisition process for acquiring map data from the base station, and FIG. 4B.
6 is a flowchart showing a transmission process in which a base station transmits map data. FIG. 5 is an example of map data of the liquid crystal display 50.

First, when the macro computer of the control circuit 80 of the mobile phone determines that the current time is the map data acquisition timing, it starts execution of the acquisition process according to the flowchart shown in FIG.

Here, the communication control unit 20 modulates the map data request signal and outputs the modulated signal (step 151). Therefore, the antenna 10 transmits the modulated signal by using the radio wave as a medium. However, the request signal includes the setting detail level of the map data and the current location.

Next, the communication control unit 2 through the antenna 10.
When the map data from the base station is received via 0, this map data is displayed on the liquid crystal display 50 (steps 152 and 153).

Here, the liquid crystal display 50 displays the current position G on the map data together with the map data, as shown in FIG. At the same time, the direction Y of the destination based on the current location is displayed, and the distance K between the current location and the destination (for example, ◯ Δm) is displayed.

Further, the base station has a map database 320 having map information corresponding to each detail level, and the base station executes the transmission process according to the flowchart shown in FIG. 4 (b). That is, when the request signal from the mobile phone is received, the setting detail level and the current location are extracted from the request signal (step 300).

Along with this, map data of a predetermined range including the present location is selected from the map database 320 and the selected map data is transmitted to the mobile phone (steps 310 and 330).

Next, a concrete example in which the time interval for obtaining the map data of the mobile phone is variable will be described with reference to FIG.

FIG. 6 is a map showing a route that a user carries a mobile phone from a departure point 53 (▲) to intermediate points 54a to 54f (■) to a destination 55 (●).

First, at the starting point 53, the map data 5 showing the starting point 53 with a detail of 1 / 50,000.
Get 30. Here, when the distance between the starting point 53 and the destination 55 is 100 km or more, the acquisition interval is 5
Set to minute and set the detail level of map data to 50
Set to 1/000.

Next, when five minutes have passed from the starting point 53 and the intermediate point 54a is reached, the map data 540a showing the intermediate point 54a with the detail of 1 / 50,000 is acquired. Here, when the distance between the intermediate point 54a and the destination 55 is less than 100 km or 50 km or more,
The acquisition interval is set to 3 minutes, and the detail level of the map data is set to 1/25000.

Next, when three minutes have passed from the waypoint 54a and the waypoint 54b is reached, the map data 540b showing the waypoint 54b with a detail of 1/25000.
To get. Here, when the distance between the intermediate point 54b and the destination 55 is less than 50 km or 20 km or more,
The acquisition interval is set to 1 minute, and the detail level of the map data is set to 1/10000.

Next, when one minute elapses from the intermediate point 54b and reaches the intermediate point 54c, the map data 540c showing the intermediate point 54c with a detail of 1/10000.
To get. Here, when the distance between the intermediate point 54c and the destination 55 is less than 20 km, the acquisition interval is 30
Set to seconds and set the detail level of the map data to 5000
Set to 1 / min. After that, the intermediate points 54d, 54e, 5
In 4f, 1/5000 map data is acquired every 30 seconds.

The features of the first embodiment will be described below. It is equipped with a mobile phone that acquires map data including the current location by wireless communication and displays a map based on the acquired map data, and calculates the distance from the current location to the destination, and depending on the distance from the current location to the destination. Then, the interval for acquiring the map data is changed.

In this way, the interval at which the map data is acquired is varied according to the distance from the current location to the destination. Since the map data is acquired at this interval, the map data can be acquired at an appropriate timing. Therefore, it is possible to reduce acquisition of map data at unnecessary timings, and it is possible to reduce communication costs and power consumption for acquiring map data.

Further, the mobile phone shortens the time interval for acquiring the map data as the distance from the present location to the destination shortens. Further, as the distance from the current position to the destination becomes shorter, detailed map data is acquired from the base station and the map data is displayed on the liquid crystal display 50.

As a result, the longer the distance from the current location to the destination, the wider the map data acquired. Therefore, even if the acquisition timing of the map data is reduced, the user can be guided to the destination satisfactorily. .

Further, in the first embodiment, the time interval for acquiring the map data is varied according to the distance from the current position to the destination, and when the time interval above the previous positioning point has elapsed, the current position is changed. Although the example of acquiring the map data shown by communication from the base station has been described, the present invention is not limited to this.
You may do as follows.

First, the microcomputer of the control circuit 80 measures the moving distance from the acquisition timing of the map data, and determines whether or not the measured moving distance is equal to or more than a predetermined threshold value (third determination). means). Then, when it is determined that the movement distance is equal to or greater than the predetermined threshold,
Get map data. Thereby, even if the elapsed time from the previous positioning point is less than the time interval, if the measured moving distance is equal to or more than the predetermined distance, the map data can be acquired again by communication.

Here, instead of the elapsed time from the previous positioning point, the distance between the departure place and the current location, the elapsed time from the departure place, the moving speed, the moving distance from when the map data is acquired, or Alternatively, the time elapsed since the map data was acquired may be adopted.

In the first embodiment, step 1
In 70, 200, and 230, the distance between the current location and the destination is divided into four stages such as 100 km or more, 50 km or more and less than 100 km, 20 km or more and less than 50 km, and less than 20 km, and the corresponding one of the divided four stages. Although the example of setting the acquisition interval of the map data based on the step is described, the present invention is not limited to this, and the following may be performed.

That is, the map data may be divided into N stages (N is a natural number) other than the above-mentioned four stages, and the map data acquisition interval may be set based on the corresponding stage of the divided N stages.

Here, steps 170, 200 and 230
In the above, as the threshold values (100 km, 50 km, 20 km) used for comparison with the distance between the current position and the destination,
The value is not limited to a fixed value and may be changed according to the user's operation on the key operation unit 60. Furthermore, the threshold value may be calculated according to the distance from the departure place to the destination.

In the first embodiment described above, an example in which the map data acquisition interval is obtained based on the distance between the current location and the destination has been described. The parameters may be adopted as follows.

For example, as the parameter, the elapsed time from the departure place, the moving speed, the moving distance from the time when the map data is acquired, and the elapsed time from the time when the map data is acquired may be adopted.

Further, the map data may be acquired every time the time set by the user has passed, or the map data may be acquired each time the distance set by the user is moved. Further, the map data may be acquired when the vehicle arrives at the point set by the user.

(Second Embodiment) In the first embodiment,
I described an example of shortening the time interval for acquiring map data as the distance from the current location to the destination becomes shorter.
In the second embodiment, an example in which it is determined whether or not map data is acquired based on the distance from the current position to the destination and the moving distance from the previous positioning point will be described.

In the second embodiment, the flowcharts shown in FIGS. 7 and 8 are adopted instead of the flowcharts shown in FIGS. 2 and 3. Step 10 shown in FIGS. 7 and 8
0, 120, 150, 160, 170, 200, 230
Are the steps 100, 120, 15 shown in FIGS.
0, 160, 170, 200, 230. Then, the control circuit 80 performs navigation processing according to the flowcharts shown in FIGS.

Next, details of the navigation processing of the second embodiment will be described with reference to FIGS. 7 and 8. First,
The control circuit 80 starts execution of the computer program according to the flowcharts shown in FIGS.

First, the operation of the built-in timer is started, and the destination is set based on the user's operation on the key operation unit 60 (step 100). Further, the latitude and longitude of the departure place are obtained based on the amplified signals from the GPS receiving unit 40, and the latitude and longitude of the departure place are stored in the memory 7.
0 (steps 120A and 121A).

Next, the map data showing the place of departure with the degree of detail of 1 / 50,000 is acquired from the base station,
It is displayed on the liquid crystal display 50. Further, the acquisition timing of map data is measured based on the operation of the built-in timer, and this acquisition timing is stored in the memory 70 (step 150A).

Next, at step 120, the latitude and longitude of the current location are obtained based on the output signal from the GPS receiving section 40. Along with this, the distance between the current location and the destination is obtained from the latitude and longitude of the current location and the latitude and longitude of the destination (step 160).

Next, the moving distance from the previous acquisition timing of map data to the current position is measured (step 40).
0). Here, in the process of the first step 400 after the start of the navigation process, the timing of the departure place is adopted as the acquisition timing of the previous map data.

Furthermore, the distance between the present location and the destination is
It is determined whether the distance is 100 km or more (step 17).
0).

Here, when the moving distance from the departure place to the present position is 100 km or more, the acquisition timing of the previous map data is called from the memory 70, and it is determined whether or not the map data has been moved by 20 km or more from the called acquisition timing. A determination is made (step 410).

Here, 20k from the previous acquisition timing
When the distance has moved by m or more, the process proceeds to step 190 and the detail level of the map data is set to 1 / 50,000. Along with this, the detail data of 1 / 50,000 and the map data indicating the current location are acquired from the base station by communication and displayed on the liquid crystal display 50 (step 150).

Next, the acquisition timing of the map data is timed based on the operation of the built-in timer, and the timed acquisition timing is stored in the memory 70 instead of the previous acquisition timing. And the latitude of the current location,
The longitude is stored in the memory 70 instead of the latitude and longitude of the place of departure (step 450). Then, it progresses to step 120.

If it is determined in step 410 that the movement distance from the previous acquisition timing is less than 20 km, the process proceeds to step 120. Thereby, acquisition of map data can be prohibited.

Further, when it is determined in step 170 that the distance between the current position and the destination is less than 100 km, the process proceeds to step 200. Here, it is determined whether or not the distance between the current location and the destination is 50 km or more.

Then, the distance between the present location and the destination is
When the distance is 50 km or more, the routine proceeds to step 420, where it is determined whether or not the vehicle has moved 10 km or more from the previous acquisition timing of map data.

Here, when moving 10 km or more from the previous acquisition timing of map data, the map data indicating the current location is acquired by communication from the base station and displayed on the liquid crystal display 50 with a degree of detail of 1/25000. (Steps 220 and 150). After that, the process proceeds to 120 through the process of step 450.

If it is determined in step 420 that the movement distance from the previous acquisition timing is less than 10 km, the process proceeds to step 120. Thereby, acquisition of map data can be prohibited.

Next, when it is determined in step 200 that the distance between the present location and the destination is less than 50 km, the process proceeds to step 230. Here, it is determined whether or not the distance between the current location and the destination is 25 km or more.

Then, the distance between the present location and the destination is
When it is 25 km or more, the process proceeds to step 430, and it is determined whether or not it has moved 5 km or more from the previous acquisition timing of map data.

Here, when the map data has moved 5 km or more from the previous acquisition timing of map data, the map data indicating the current location is acquired by communication from the base station and displayed on the liquid crystal display 50 with a detail of 1/10000. (Steps 250 and 150). After that, the process proceeds to step 120 through the process of step 450.

If it is determined in step 430 that the moving distance from the previous acquisition timing is less than 5 km, the process proceeds to step 120. Thereby, acquisition of map data can be prohibited.

Next, in step 230, when it is determined that the distance between the current position and the destination is less than 25 km, the process proceeds to step 440. Here, it is determined whether or not the vehicle has moved by 1 km or more from the previous acquisition timing of map data.

Here, when the vehicle has moved 1 km or more from the previous acquisition timing of map data, the map data indicating the current location is acquired by communication from the base station and displayed on the liquid crystal display 50 with a degree of detail of 1/5000. (Steps 270, 150). After that, the process proceeds to step 120 through the process of step 450.

If it is determined in step 440 that the moving distance from the previous acquisition timing is less than 1 km, the process proceeds to step 120. Thereby, acquisition of map data can be prohibited.

The features of the second embodiment will be described below. That is, the microcomputer of the control circuit 80 determines that the distance from the current location to the destination is the first threshold value (100
(km, 50 km, 25 km) or more. In addition, the distance traveled since the map data was acquired is the second
Is greater than or equal to the threshold value of (20 km, 10 km, 5 km, 1 km). Here, when the distance to the destination is equal to or larger than the first threshold and the movement distance is equal to or larger than the second threshold, the map data is acquired and displayed on the liquid crystal display 50.

Therefore, the current location is the liquid crystal display 50.
Compared to the case where map data is acquired every time it is out of the range of the map data displayed in, useless map data acquisition timing can be reduced, and communication cost and power consumption for acquiring map data are reduced. can do.

Further, as the distance from the present location to the destination becomes shorter, detailed map data is acquired from the base station and displayed on the liquid crystal display 50. As a result, the shorter the distance from the current location to the destination, the better the guidance of the user to the destination.

Here, the above-mentioned second threshold value is set so that it becomes smaller as the distance from the current position to the destination becomes shorter, so that the shorter the distance to the destination becomes, the smaller the moving distance becomes. Since the map data can be acquired, the user can be better guided as the destination gets closer.

In each of the above-mentioned embodiments, an example in which the map display device is applied to a mobile phone has been described, but the present invention is not limited to this, and is applied to various devices such as a portable device such as PHS and PDA, a car navigation device and the like. Good.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a mobile phone according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a part of the operation of the control circuit shown in FIG.

3 is a flowchart showing the rest of the operation of the control circuit shown in FIG.

FIG. 4 is a flowchart showing details of the flowchart shown in FIG.

5 is a diagram showing a display of the liquid crystal display shown in FIG. 1. FIG.

FIG. 6 is a view for explaining the operation of the first embodiment.

FIG. 7 is a flowchart showing a part of the operation of the mobile phone according to the second embodiment of the present invention.

FIG. 8 is a flowchart showing the rest of the operation of the mobile phone according to the second embodiment.

[Explanation of symbols]

50 ... Liquid crystal display, 60 ... Key operation part, 80 ... Control circuit.

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Claims (7)

[Claims] 1. A map display device having an acquisition means (152) for acquiring map data including a current location by wireless communication, and displaying a map based on the acquired map data, the destination being from the current location. And a variable unit (180, 210, 240, 260) for varying the interval at which the acquisition unit acquires the map data according to the distance from the current position to the destination. And a map display device. 2. A first determining means (1) for determining whether or not the current location is out of the range of the displayed map data.
30) and second determination means (140) for determining whether or not the interval set by the setting means has elapsed, and the map data in which the current location is displayed by the first determination means. When it is determined that the distance is out of the range, and when the second determination means determines that the interval set by the setting means has elapsed, the acquisition means acquires the map data. The map display device according to claim 1. 3. A third determination unit that determines a movement distance from the time of acquisition of the map data and determines whether or not the calculated movement distance is equal to or greater than a predetermined threshold value, the acquisition unit includes: The map display device according to claim 1 or 2, wherein the map data is acquired when the movement distance is determined to be equal to or greater than a predetermined threshold value by the third determination means. 4. The method according to claim 1, wherein the shorter the distance from the current location to the destination, the shorter the interval at which the acquisition means acquires the map data. The map display device according to any one of 3 above. 5. A display means (50) for displaying and an acquisition means (152) for acquiring map data indicating a current location by wireless communication, and the map display means for displaying the map based on the acquired map data. A map display device to be displayed on the display device, comprising: first measuring means (160) for measuring a distance from the current location to a destination; and determining whether the distance to the destination is equal to or more than a first threshold value. First determining means (170, 200, 230)
A means (400) for obtaining a moving distance from the time of acquisition of the map data, and a second judging means (410, 420, 430, 440) for judging whether or not the moving distance is a second threshold value or more. ) And the distance to the destination is determined to be equal to or greater than a first threshold by the first determination means, and the movement distance is equal to or greater than a second threshold by the second determination means. The map display device, wherein the acquisition means acquires the map data and outputs the map data to the display means. 6. The map display device according to claim 5, wherein the second threshold value is set to be smaller as the distance from the current location to the destination is shorter. 7. The detail of the map data acquired by the acquisition means is set to increase as the distance from the current position to the destination decreases. The map display device described in any one.