JP2001147121A - Map data distribute center and navigation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce excellently a memory capacity required to the navigation device side, and simultaneously to enable the navigation device to obtain the newest map data from a map data distribution center. SOLUTION: In this processing, map data of nine map blocks including the present position among the map data distributed from a broadcasting station are stored in a storage medium. For example, supposing the present position is a position shown by A, the map data of nine map blocks shown by 4, 5, 6, 7, 8, 9, 7', 8', 9' are stored. When the present position is moved from A to B, the map data of map blocks 1', 2', 3' are newly stored, and the map data of the map blocks 7', 8', 9' are deleted from a memory region of the storage medium. As only the map data of required map blocks are stored in this way, the memory capacity required in the storage medium can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map data distribution center for distributing map data and a navigation device for receiving the distributed map data and guiding a user. The present invention relates to a map data distribution center and a navigation device that are divided for each.

[0002]

2. Description of the Related Art Conventionally, a car navigation apparatus detects the current position of a vehicle using a GPS (Global Positioning System) or the like, reads map data corresponding to the position from a CD-ROM or the like, and reads the current data. It is displayed along with the position. However, when map data is stored in advance on a CD-ROM or the like, it is difficult to store detailed map data for the whole of Japan or when a change in road conditions occurs, a new CD-ROM is used. May need to be replaced. Therefore, it has been considered that map data is distributed from a map data distribution center fixed on the ground, and the car navigation device receives the map data and guides the driver based on the map data.

Further, as described in, for example, Japanese Patent Application Laid-Open No. H11-15372, map data is distributed from a map data distribution center in each area, and based on the data,
Updating the map data stored in the car navigation device for each area has also been considered. In this case, it is possible to cope with a change in road conditions or the like with a small amount of communication compared to a case where all the map data stored in the car navigation device is received from the map data distribution center and updated as a whole. .

[0004]

However, in any case, it is necessary for the car navigation device to store map data corresponding to many areas, such as blocks arranged in a matrix. For this reason, the map data of the area irrelevant to the moving route from the current position to the destination is also stored, and the storage area of the car navigation device is overwhelmed. For this reason, conventionally, it was necessary to prepare a storage capacity much larger than the storage capacity required for guiding the user to the destination in the storage area on the car navigation device side. In addition, this problem occurs not only in a car-mounted navigation device but also in a portable navigation device.

Accordingly, an object of the present invention is to make it possible for a navigation apparatus to obtain the latest map data from a map data distribution center while favorably reducing the storage capacity required for the navigation apparatus.

[0006]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a database which stores map data by dividing the map data into sections, and a database which stores the map data. The gist is a map data distribution center including a distribution unit for sequentially and repeatedly distributing map data of an area together with an ID designating the area corresponding to the map data.

In the present invention having the above-described structure, the map data for each area distributed by the distribution means is attached with an ID indicating which area the map data corresponds to. For this reason, the navigation device can store only the map data necessary for guiding the user by referring to the ID of the received map data. Therefore, according to the present invention, the navigation device can obtain the latest map data from the map data distribution center of the present invention, while favorably reducing the storage capacity required for the navigation device.

Further, according to the present invention, it is possible to determine to which area the map data corresponds with the ID, so that the distribution of the map data as in the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 11-15372 is disclosed. There is no need to set a schedule, and the map data of each area is sequentially and repeatedly delivered from the map data delivery center of the present invention. For this reason, the navigation device can always receive the map data of the desired area, and the data amount of the map data that must be stored and stored in the navigation device can be further reduced. Therefore, according to the present invention, the storage capacity required for the navigation device can be further reduced.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the map data stored in the database and which can be distributed by a map data distribution center adjacent to another map data distribution center. Partly overlaps with the target range of data. For this reason, in the present invention, in addition to the effect of the invention described in claim 1, there is an effect that necessary map data can be smoothly provided without interruption even when the navigation device moves across the target range. Occurs.

[0010] The third aspect of the present invention is the first or second aspect.
In addition to the configuration described above, the distribution means is configured to be capable of distributing the map data via radio waves of a plurality of frequencies, and allocates a frequency to be used according to the area. In the present invention, since the frequency used when distributing the map data is allocated according to the area, the cycle at which the map data of each area is repeatedly distributed can be shortened.
Therefore, according to the present invention, in addition to the effects of the first and second aspects of the present invention, there is an effect that map data required on the navigation device side can be obtained more quickly. For this reason, the data amount of map data that must be stored and stored on the navigation device side can be further reduced, and the storage capacity required on the navigation device side can be further reduced. can do.

According to a fourth aspect of the present invention, there is provided a position detecting means for detecting its own current position, a receiving means for receiving the map data together with the ID, and an ID of the received map data.
Is a first determining means for determining whether or not the area belongs to the vicinity of the current position detected by the position detecting means, and a map having an ID determined by the first determining means to correspond to the corresponding area. The gist is a navigation device including a storage unit for storing data.

In the present invention, since the storage means stores the map data determined to correspond to the vicinity of the current position by the first determination means, the map data corresponding to the area remote from the current position may not be stored. And the storage capacity of the storage means can be reduced favorably. Further, according to the present invention, fresh map data can always be obtained from the map data distribution center via the receiving means. Therefore,
According to the present invention, the latest map data can be made available from the map data distribution center while the storage capacity required for the navigation device is reduced favorably.

According to a fifth aspect of the present invention, there is provided the same position detecting means and receiving means as in the fourth aspect of the present invention, and a route acquisition for acquiring a moving route from the current position detected by the position detecting means to the destination. Means for determining whether or not the ID of the map data received by the receiving means corresponds to the map data of the area including the travel route obtained by the route obtaining means; and the second determining means Storage means for storing map data having an ID determined to correspond to the above by the means.

According to the present invention, when the moving route acquiring means acquires the moving route from the current position to the destination, the storing means:
The map data having the ID determined to correspond to the map data of the area including the movement route by the second determination means is stored. For this reason, the storage means does not need to store the map data corresponding to the area distant from the moving route, and the storage capacity of the storage means can be favorably reduced. Further, according to the present invention, fresh map data can always be obtained from the map data distribution center via the receiving means. Therefore, according to the present invention, the latest map data can be made available from the map data distribution center while the storage capacity required for the navigation device is reduced favorably. In addition, when map data of an area including a moving route is received in advance, the process related to the above-described guidance is performed more smoothly than when map data near the current position is sequentially received while guiding the user. be able to.
Further, it is easy to confirm the entire movement route on a map.

According to a sixth aspect of the present invention, in addition to the configuration of the fifth aspect, the route acquiring means acquires the movement route by performing bidirectional communication with an information center different from the map data distribution center. The configuration has In the present invention, since the moving route acquisition means acquires the moving route by performing two-way communication with the information center, it is not necessary for the moving route acquiring means to perform complicated processing such as route calculation. The configuration can be further simplified. Therefore, in addition to the effect of the fifth aspect of the present invention, there is an effect that the configuration of the device can be further simplified and the storage capacity can be further reduced. In addition, since the information center is different from the map data distribution center, stable control can be performed without confusion between the map data and the data of the travel route.

According to a seventh aspect of the present invention, in addition to the configuration of any of the fourth to sixth aspects, the map data stored in the storage means has already passed through based on the detection result of the position detection means. A third determining means for determining whether or not the data is the map data of the passed area, and when the third determining means determines that the data is the map data of the passed area, the map data is deleted from the storage area of the storage means. And deleting means.

In the present invention, the deletion means deletes the map data determined as belonging to the area already passed by the third determination means from the storage area of the storage means. That is,
Since the map data of the already passed area is not necessary for guiding the user, the data is deleted from the storage area of the storage means. For this reason, in the present invention, in addition to the effect of the invention according to any one of claims 4 to 6, an effect that the storage capacity can be further reduced can be obtained.

According to an eighth aspect of the present invention, in addition to the configuration of the seventh aspect, a designating means for designating a desired area in which the map data is to be always stored and registered, and the map data stored in the storage means. And a fourth determining means for determining whether or not the data is the map data of the desired area. The map data determined by the deleting means as the map data of the desired area by the fourth determining means is It is not deleted from the storage area of the storage means.

In the present invention, the deleter does not delete the map data determined by the fourth determiner as the map data of a desired area that is to be constantly stored and registered from the storage area of the storage. Therefore, in the present invention, in addition to the effect of the invention described in claim 7, the map data of the desired area specified in advance by the specifying means can be immediately read out from the storage means at any time without receiving. There is an effect that can be performed.

According to a ninth aspect of the present invention, in addition to the configuration of the eighth aspect, when the receiving means receives the map data already stored in the storage means as the map data of the desired area, The storage means has a configuration in which the received map data is not newly stored.

If the map data of the desired area is already stored in the storage means as described above, even if the reception means receives the map data, the storage means does not need to store the data again. . Therefore, in such a case, in the present invention, the storage unit does not newly store the received map data. Therefore, in the present invention, in addition to the effect of the invention described in claim 8, there is an effect that extra processing can be omitted to speed up the processing.

[0022]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram schematically showing a configuration of a navigation system to which the present invention is applied. As shown in FIG. 1, the system according to the present embodiment includes:
The main components are an in-vehicle system 1 as a navigation device, a broadcasting station 31 as a map data distribution center, a mobile phone base station 41 and an information center 51.

The on-vehicle system 1 includes a GPS antenna 2 for receiving radio waves from a satellite, and a broadcasting station 3 via an antenna 3.
A mobile phone 6 (which may be a car phone) which performs two-way communication with a mobile phone base station 41 of a mobile phone carrier via an antenna 5;
It has. The mobile phone 6 is connected to the in-vehicle computer 1 via a communication unit 7 for controlling communication by the mobile phone 6.
1, the vehicle-mounted computer 11 further stores the GPS antenna 2 and the receiver 4 described above, a storage medium 12 for storing map data and the like described later, and a road map corresponding to the map data together with the current position of the vehicle. A display 13 for displaying a destination selection screen or the like and a remote controller 14 for inputting various commands from a user are connected.
The in-vehicle computer 11 includes a CPU, ROM, RA
It is constituted by a microcomputer having M as a main part, and executes various processes described later.

The broadcasting station 31 divides the map data into predetermined map blocks (areas) and stores the divided data.
And the map data from the database 33,
Broadcast server 35 that performs processing such as processing for distribution
And the map data processed by the broadcast server 35 to the antenna 3
9 and a broadcast device 37 for distributing at a predetermined frequency.

The broadcasting station 31 is provided in units of prefectures, and the database 33 stores map data of a target area including an adjacent prefecture divided into, for example, approximately square map blocks of 10 km square. Here, the size of the map block does not need to be uniform, and the distance of one side may be long in a suburb and the distance of one side may be short in an urban area. An ID is assigned to each map block, and the broadcast server 35 reads out the ID together with the map data of each map block, and sequentially distributes the ID via the broadcast device 37.

The mobile phone base station 41 is configured to be capable of two-way communication with the mobile phone 6 via the antenna 43, and is also connected to the information center 51 via the general subscriber telephone network 45 so as to be communicable. The information center 51 includes a database 53 that stores map data substantially similar to the database 33 of the broadcast station 31 and name index data described below, an information server 55 that reads various data from the database 53 and performs route calculation and the like, A communication server 57 for converting the travel route and the like calculated by the server 55 into communication data and controlling other communication; and transmitting the converted communication data to the general subscriber's telephone network 45 and the mobile phone base station. A transmission / reception device 5 for transmitting to the in-vehicle system 1 via the communication system 41 or receiving data such as a destination transmitted from the in-vehicle system
9 is provided.

Next, the processing executed by the on-vehicle computer 11 in the navigation system thus configured will be described with reference to the flowchart of FIG.
FIG. 2 shows a process related to the reception of the map data distributed from the broadcast station 31 among the processes executed by the on-board computer 11.

When the power of the on-vehicle system 1 is turned on, the on-vehicle computer 11 first executes the processing of S1 (S represents a step: the same applies hereinafter), and responds to the operation of the remote controller 14 by the user as follows. Make initial settings. That is, no map data is stored in the storage medium 12 of the in-vehicle system 1 at the time of shipment. The in-vehicle system 1 executes a well-known navigation process (guidance) based on the map data received from the broadcasting station 31. However, an area (for example, around the home) that is always required to be stored in the storage medium 12
The ID of the map data is registered in this S1. As a registration method, the user may directly input the ID using the ten keys or the like of the remote controller 14 or may input the ID using the place name. Further, the process of S1 may be always executed when the power is turned on, or once set at the time of purchase, S1 may be skipped (skipped) thereafter. The user can select any desired form by setting.

At S3, the map data distributed from the broadcasting station 31 is received. At S5, it is determined whether or not the ID attached to the map data is the permanent storage registration ID registered at S1. . If it is not a permanent storage registration ID (S
5: NO), in S7, it is determined whether or not the ID is the map data ID corresponding to the map block near the current position. That is, the current position of the vehicle is detected via the GPS antenna 2, and the received ID is an ID corresponding to one of a map block including the current position and eight map blocks around the map block. It is determined whether or not.

If it is not the ID of the map block near the current position (S7: NO), the process proceeds to S3 without storing the map data, and the next map data is received.
In many cases, the process waits until the necessary map data is distributed from the broadcast station 31 while repeating the loop processing of S3 to S7.

On the other hand, the ID attached to the map data received in S3 is not the permanent storage registration ID (S5: N
O), if it is the ID of a map block near the current position (S7: YES), the process proceeds to S9, where the map data is stored and stored in the storage medium 12. In subsequent S11, it is determined whether or not the data of the map block other than the vicinity of the current position is stored in the storage medium 12, and if not stored (NO), the process proceeds to S3 as it is (YES). ) Goes to subsequent S13. S1
In 3, it is determined whether or not the ID of the map data being stored is the above-described permanent storage registration ID. If the ID is the permanent storage registration ID (YES), the map data is not stored (NO). After the map data is deleted from the storage area of the storage medium 12 in S15, the process proceeds to S3. As a result, map data that does not correspond to the map block near the current position and does not correspond to the permanent storage registration ID,
The data is deleted from the storage area of the storage medium 12.

If the ID attached to the map data received in S3 is a permanent storage registration ID (S5: Y
ES), the process proceeds to S17, and the map data is stored in the storage medium 1
It is determined whether or not the data is already stored in the storage device 2 and stored. If the data is not being stored (NO), the data is stored in S9, and if the data is being stored (YES), the process proceeds to S11 as it is. By the above processing, only the map data corresponding to the map block near the current position and the map data corresponding to the permanent storage registration ID are stored in the storage area of the storage medium 12.

As described above, the map data corresponding to the map block near the current position is stored and stored in the storage medium 12, so that the on-board computer 11 displays the current position of the vehicle together with the road map in the vicinity. 13 can be displayed. In addition, when the user uses the display 1
When the destination is set by calling a destination selection screen or the like in Step 3, the in-vehicle computer 11 also displays the direction in which the vehicle should travel on the display 13 together with the current position and the road map.

Here, the operation of setting the destination will be described. When setting a destination, the user must use the remote control 1
A predetermined operation is performed on the information center 4 to request name index data from the information center 51 via the mobile phone 6 and the mobile phone base station 41. Then, the information server 55 of the information center 51 reads out the name index data stored in the database 53,
Return to in-vehicle system 1. As a result, a destination selection screen including a data list is displayed on the display 13, and the user selects and sets a desired destination from the destination selection screen. Then, the in-vehicle computer 11 transmits the destination and the current position detected via the GPS antenna 2 to the information center 51. The information center 51 calculates a route from the current position to the destination based on the map data stored in the database 53, and returns the calculated travel route to the on-vehicle computer 11. When the movement route is calculated in this way, the on-board computer 11 displays the current position, the road map, and the direction in which the vehicle should travel on the display 13. As a result, the user can be properly guided to the destination.

Next, the storage / deletion of the map data (S
The operation and effect of (9, S15) will be described in more detail. As described above, in the processing of FIG. 2, map data of nine map blocks including the current position is stored in the storage medium 12. For example, when the current position is the position indicated by A in FIG. 3, map data of nine map blocks represented by 4, 5, 6, 7, 8, 9, 7 ', 8', 9 'is stored in a storage medium. 12 is stored.

Here, considering the case where the current position moves from A to B, in this case, the map blocks represented by 1 ', 2', and 3 'are newly added to the map blocks (S
7: YES) and stored in the storage medium 12 (S9). On the other hand, since the map blocks represented by 7 ', 8', and 9 'are not map blocks near the current position (S11: YES), unless these map blocks always correspond to the storage registration ID (S13). : NO),
The map data is deleted from the storage area of the storage medium 12 (S15). As a result, 9 including the new current position B is obtained.
Map blocks 1 ', 2', 3 ', 4, 5, 6, 7,
The map data 8 and 9 are stored in the storage area of the storage medium 12.

As described above, in the vehicle-mounted system 1 according to the present embodiment, only the map data of the nine map blocks including the current position and the map data corresponding to the preset permanent storage registration ID are stored in the storage medium. 12
Unnecessary data corresponding to a map block distant from the current position can be not stored, and the storage capacity required for the storage medium 12 can be reduced favorably. In addition, since the latest map data is always received from the broadcast station 31, it is possible to execute a guide that responds immediately to a change in road conditions or the like. In addition, map data of a map block that is no longer a map block near the current position (for example, a map block that the vehicle has passed just before) is deleted from the storage area unless it always corresponds to the storage registration ID. The storage capacity can be reduced more favorably.

Further, in the on-vehicle system 1, since the map data corresponding to the permanent storage registration ID is stored without being deleted, the map data corresponding to the permanent storage registration ID is always available immediately without receiving the broadcast. Can be read from the storage medium 12. For this reason, even if the broadcast is not always received, a road map can be displayed and the vehicle can be driven at any time within a certain range (for example, around the home). Further, when the map data corresponding to the permanent storage registration ID is received (S5: YES), if the map data is already stored in the storage medium 12 (S17: YES), the in-vehicle computer 11 performs the process. Map data storage processing (S
9) is skipped. For this reason, an unnecessary process can be omitted and the process can be speeded up.

Further, in the vehicle-mounted system 1, the information center 5
By performing two-way communication with the device 1, a moving route from the current position to the destination is obtained. Therefore, there is no need to execute complicated processing such as route calculation on the in-vehicle system 1, and the configuration of the in-vehicle system 1 is further simplified, and the storage capacity required for the in-vehicle system 1 is further reduced. can do. Further, since the information center 51 is provided as a facility separate from the broadcasting station 31, stable control can be performed without the confusion between the map data and the data of the travel route.

In the navigation system according to the present embodiment, the broadcasting station 31 attaches an ID to the map data to indicate which map block the map data corresponds to, and sequentially transmits the map data and the ID. Has been repeatedly delivered. For this reason, the in-vehicle system 1 can obtain map data of a desired map block very easily, and can further reduce the storage capacity more favorably.

That is, the above-mentioned JP-A-11-15372
In the case of distributing map data according to a predetermined distribution schedule as in the technology described in Japanese Unexamined Patent Publication, there is a possibility that it is necessary to wait for a long time until the desired map data is distributed. Needs to be stored in the storage medium 12 in advance. On the other hand, in the present embodiment, since the broadcasting station 31 sequentially and repeatedly distributes the map data of each map block together with the ID,
The in-vehicle system 1 can receive desired map data at any time, and sufficient guidance can be provided by storing nine pieces of map data as described above. Note that the broadcasting station 31 may sequentially and repeatedly deliver the map data at predetermined time intervals. Furthermore, since the broadcast station 31 also distributes map data of an adjacent prefecture, the necessary map data can be smoothly provided without interruption even when the in-vehicle system 1 moves across prefectures.

In the above embodiment, the broadcast server 35 and the broadcast device 37 serve as the distribution means, the GPS antenna 2 serves as the position detecting means, the antenna 3 and the receiver 4 serve as the receiving means, and the processing in S7 is the first judgment. Means, the storage medium 12 as the storage means, the antenna 5 and the mobile phone 6 as the route obtaining means, the processing at S11 as the third determining means, the processing at S15 as the deleting means, the processing at S1 and the remote controller 14 as the specifying means. To
The processing of S13 corresponds to the fourth determination means. Further, the present invention is not limited to the above-described embodiment at all, and can be implemented in various forms without departing from the gist of the present invention. For example, in the above-described embodiment, the user is guided by the display 13, but the voice may be guided together, or the voice may be guided only.

Further, in the above embodiment, the map data corresponding to the nine map blocks centering on the map block including the current position is stored, but the method of setting the stored map blocks is not limited to this. There are various possibilities. For example, 25 map blocks around the map block including the current position may be stored.

As shown in FIG. 4, when the moving route 91 from the current position C to the destination D is acquired, the map data of the map block including the moving route 91 such as the map block 92 is stored. All may be kept. Again,
The map data corresponding to the map block distant from the movement route 91 can be left unstored, and the storage capacity required for the storage medium 12 can be reduced favorably. Further, when the map data of the map block including the movement route 91 is stored in advance in this way, the processing related to the above guidance is performed more smoothly than in the case where the map data near the current position is sequentially received as described above. Can be performed. In addition, it is easy to check the entire travel route on a map.

Further, when the map data of the map block including the moving route 91 is stored in advance in this manner, as shown in FIG. 5, even the map block near the current position does not include the moving route 91. May not be stored. In this case, similarly to the embodiment of FIG. 4, the processing relating to the guidance can be smoothly performed, and the storage capacity required for the storage medium 12 can be further reduced.
In such a process, it is determined whether or not the ID of the map block including the moving route is determined in S7 of FIG. 2 and whether the map data of the map block not including the moving route is being stored in S11 of FIG. It can be executed if it is determined. In this case, S7 after the change corresponds to the second determination unit. If the “moving route” in the above determination is defined as a route from the current position at that time to the destination along with the movement of the vehicle, the data of the map block after passing can be deleted in S15. .

Further, the processing mode shown in FIG. 4 and the processing mode shown in FIG. 5 can be switched according to the setting of the user. Further, in this case, when the remaining capacity of the storage medium 12 decreases for some reason, the processing mode of FIG. 4 may be automatically switched to the processing mode of FIG.

In the case where the number of map blocks in the target range of the broadcasting station 31 is so large that the distribution cycle of the desired map data becomes long and the distribution of the map data cannot be made in time for the running of the vehicle, the target range is divided. Alternatively, map data of each area divided by different channels (frequency) may be sequentially and repeatedly delivered for each map block. In this case, the cycle at which the map data of each map block is repeatedly delivered can be shortened, so that the required map data can be quickly obtained.

In this case, the data amount of the map data that must be stored in the storage medium 12 can be reduced more favorably, and the storage capacity can be further reduced. Further, when the broadcasting station 31 uses a different channel for each area as described above, or when the broadcasting stations 31 provided in each prefecture use different channels, when moving across the area or the prefecture, The vehicle-mounted system 1 may be provided with channel switching means for automatically switching channels.

Further, the present invention can be applied not only to a so-called car navigation apparatus mounted on a car but also to a portable navigation apparatus. The map data distribution center distributes map data not only by radio waves but also by an optical beacon or the like. May be used. Further, the number of map blocks stored as map data in the storage medium 12 may be changed according to the vehicle speed. For example, when storing the map data of the map blocks near the current position, storing the map data of a larger number of map blocks as the vehicle speed increases makes it more favorable that the distribution of the map data cannot be made in time for the vehicle to run. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a functional block diagram schematically showing a configuration of a navigation system to which the present invention is applied.

FIG. 2 is a flowchart showing a process executed by the on-board computer.

FIG. 3 is an explanatory diagram showing data stored in a storage medium in the processing.

FIG. 4 is an explanatory diagram showing data stored in another form of the processing.

FIG. 5 is an explanatory diagram showing data stored in still another form of the processing.

[Explanation of symbols]

1. In-vehicle system 2 .... GPS antenna 3, 5,
39, 43 ... Antenna 4 ... Receiver 6 ... Mobile phone 7 ... Communication unit
DESCRIPTION OF SYMBOLS 11 ... In-vehicle computer 12 ... Storage medium 13 ... Display 14 ... Remote control 31 ... Broadcasting station 33, 53 ... Database 35 ... Broadcast server
37 Broadcasting device 41 Cellular base station 45 General subscriber telephone network
51 information center 55 information server 57 communication server
59 ... Transceiver

Claims (9)

[Claims] A map data distribution center for distributing the map data to a navigation device for guiding a user based on the received map data, wherein the database stores the map data divided for each area; And a distribution means for sequentially and repeatedly distributing map data of each area stored in the database together with an ID designating the area corresponding to the map data, and a distribution means. 2. The target range of the map data stored and distributable in the database partially overlaps with the target range of the map data distributable by another adjacent map data distribution center. Item 2. The map data distribution center according to item 1. 3. The distribution means according to claim 1, wherein said distribution means is configured to distribute said map data via radio waves of a plurality of frequencies, and distributes a frequency to be used according to said area. Map data distribution center. 4. A navigation device capable of receiving map data distributed from the map data distribution center according to claim 1, and guiding a user based on the received map data, Position detecting means for detecting its own current position; receiving means for receiving the map data together with the ID; and ID of the received map data corresponding to the area corresponding to the vicinity of the current position detected by the position detecting means. First judging means for judging whether or not the area is the one corresponding to the above-mentioned area.
A storage device for storing map data having D. A navigation device comprising: 5. A navigation device capable of receiving map data distributed from the map data distribution center according to claim 1, and guiding a user based on the received map data, Position detecting means for detecting its own current position; route obtaining means for obtaining a moving route from the current position detected by the position detecting means to the destination; receiving means for receiving the map data together with the ID; Second determining means for determining whether or not the ID of the received map data corresponds to the map data of the area including the moving route acquired by the route acquiring means, and wherein the second determining means corresponds to the above. Storage means for storing map data having an ID determined to be a navigation device. 6. The navigation device according to claim 5, wherein the route acquiring means acquires the moving route by performing two-way communication with an information center different from the map data distribution center. 7. Based on the detection result of the position detecting means,
Third determining means for determining whether or not the map data stored in the storage means is map data for an area that has already passed; and when the third determining means determines that the map data is for the area that has passed. 7. The navigation device according to claim 4, further comprising: a deletion unit that deletes the map data from the storage area of the storage unit. 8. A designating means for designating a desired area in which map data is to be always stored and registered, and whether or not the map data stored in the storage means is the map data of the desired area. A fourth judging means for judging, wherein the deleting means does not delete the map data judged as the map data of the desired area by the fourth judging means from the storage area of the storage means. Claim 7
A navigation device as described. 9. When the receiving means receives map data already stored in the storage means as map data of the desired area, the storage means does not newly store the received map data. 9. The method according to claim 8, wherein
A navigation device as described.