WO2010113577A1

WO2010113577A1 - Map distribution apparatus, map distribution method, and computer program

Info

Publication number: WO2010113577A1
Application number: PCT/JP2010/053182
Authority: WO
Inventors: Mitsuhiro Naito
Original assignee: Aisin Aw Co., Ltd.
Priority date: 2009-03-31
Filing date: 2010-02-22
Publication date: 2010-10-07
Also published as: JP2010237444A

Abstract

When new map data is registered, a pre-preparation target navigation device, for which map update data is generated before an update request is received, is identified on the basis of an identified new map area and saved location information in each navigation device. If an application required for updating map data of the new map area is not installed in the pre-preparation target navigation device, distribution-purpose data that includes map update data and required application data to be distributed to the navigation device is created before reception of a distribution request, and stored in a distribution-purpose data storage database.

Description

DESCRIPTION

MAP DISTRIBUTION APPARATUS, MAP DISTRIBUTION METHOD, AND

COMPUTER PROGRAM

TECHNICAL FIELD

[0001] The present invention relates to a map distribution apparatus, a map distribution method, and a computer program, which distribute map update data for updating map data stored in a terminal in accordance with a request from the terminal.

BACKGROUND ART

[0002] Recently, navigation devices that perform vehicle travel guidance so that a driver can reach a desired destination easily are often installed in vehicles. Here, a navigation device is a device which is capable of detecting the current position of a vehicle using a GPS receiver or the like, obtaining map data corresponding to the current position from a recording medium such as a DVD-ROM or an HDD, or through a network, and displaying the obtained map data on a liquid crystal monitor. The map data including the current position of the vehicle are read from the recording medium or the like, and on the basis of the map data, a map image of the periphery of the current vehicle position is drawn and displayed on a display device. At the same time, a vehicle position mark is superposed on the map image, and as the vehicle moves, the map image is scrolled, or the map image is fixed on the screen and the vehicle position mark is moved. Thus, the current location of the moving vehicle can be learned at a glance, hi recent years, cellular telephones, personal digital assistants (PDAs), personal computers and the like often have a function similar to the navigation device above.

[0003] Throughout Japan, new roads are constructed every year. At the same time, existing roads are destroyed and the shape of existing roads is modified. In this case, a problem arises in that information relating to new roads and the like constructed after the map data of the navigation device or the like have been generated is not recorded in the map data, hi other words, in a navigation device or the like storing map data that does not include new roads and the like, the new roads are not displayed on the liquid crystal monitor, and since the new roads are not included in route searches, the navigation device finds circuitous recommended routes that do not pass along the new roads. To avoid this problem, the map data stored in the navigation device or the like must be updated at intervals of a certain time period. Here, map data updating is performed by purchasing a new map data storage medium and replacing the old storage medium with the new storage medium, or overwriting the map data in the navigation device or the like on the basis of update-purpose map data (to be referred to hereafter as map update data) distributed from a map information distribution center or the like. [0004] Differential updating is one method for updating the map data in the navigation device or the like using the map update data distributed from the map information distribution center. According to this method, only the map data of part of an area requested by the navigation device or the like is updated among the map data in the navigation device (see Japanese Patent Application Publication No. JP-A-2008-3417, pages 16 to 18 and FIG. 4).

[0005] In differential updating, to update (read, convert, and so on) map data based on the map update data received by the navigation device or the like, an application (program) that corresponds to the map update data is required. Therefore, to update map data on the basis of new map update data (e.g. map update data that updates an area with newly registered map data) that does not correspond to a current application in the navigation device or the like, the navigation device must obtain a new application. Thus, in related art, when distributing new map update data to the navigation device or the like, the map information distribution center creates and distributes distribution-purpose data that includes application data corresponding to the new map update data in the map update data. Specifically, a distribution-purpose data creation process includes a process for reading application data that corresponds to the generated map update data from a database or the like, a process for creating distribution-purpose data by combining the read application data and the map update data, and a process for performing a subsequent error check of the distribution-purpose data. The distribution-purpose data creation process is executed each time there is a map update data distribution request from the navigation device or the like.

[0006] However, the size of the application data is large, so the map distribution apparatus bears a large processing load while executing the distribution-purpose data creation process, especially during the process for reading the application data from the application data database and the process for performing the error check. As a consequence, creating the distribution-purpose data each time there is a map update data distribution request from the navigation device or the like as in the past results in a longer response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data.

[0007] Delayed distribution of the distribution-purpose data creates the following problems in particular when updating the map data stored in the navigation device. Namely, delayed distribution of the distribution-purpose data results in a significant amount of time passing after the distribution request of a vehicle until the map data update process is performed. Consequently, there may be a period during which the navigation device cannot be used due to updating of the map data while the vehicle is traveling, and such a period of unavailability can interfere with the user's vehicle travel.

[0008] A problem may also arise if the distribution-purpose data on all areas for which there may be an update request from the navigation device or the like is created and stored in advance, as this requires an extremely large memory area to store the distribution-purpose data.

DISCLOSURE OF THE INVENTION

[0009] The present invention was devised in order to solve the above problems with related art, and it is an object of the present invention to provide a map distribution apparatus, a map distribution method, and a computer program which, if new map data is registered, create and store in advance distribution-purpose data that includes map update data for updating the map data of an area with newly registered map data and includes program data for executing in a terminal an update of map data based on the map update data, so as to suppress the volume of distribution-purpose data created in advance and shorten the response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data.

[0010] hi order to achieve the above object, a map distribution apparatus according to a first aspect of the present invention is a map distribution apparatus that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal. The map distribution apparatus is characterized by including: a new map area identification unit that, if new map data is registered, identifies an area that is included in the registered new map data as a new map area; a terminal identification unit that identifies a terminal in which the standard update area includes at least a portion of the new map area; a map update data generation unit that, if a program for updating the map data of the new map area in the terminal identified by the terminal identification unit requires updating, generates map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified by the terminal identification unit; a program data generation unit that, if a program for updating the map data of the new map area in the terminal identified by the terminal identification unit requires updating, generates program data for updating the program; a distribution-purpose data creation unit that creates distribution-purpose data that includes the map update data generated by the map update data generation unit and the program data generated by the program data generation unit; a data storage unit that stores the distribution-purpose data created by the distribution-purpose data creation unit; and a data distribution unit that, if there is a distribution request from the terminal identified by the terminal identification unit for map update data to update the map data of the standard update area that includes a saved location of the terminal, distributes the distribution-purpose data stored by the data storage unit to the terminal.

Note that the term "saved location" refers to a point that is registered in advance by a user, e.g. the user's home or the user's workplace.

[0011] A map distribution method according to a second aspect of the present invention is a map distribution method that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal. The map distribution method is characterized by including the steps of: identifying, if new map data is registered, an area that is included in the registered new map data as a new map area; identifying a terminal in which the standard update area includes at least a portion of the new map area; generating, if a program for updating the map data of the new map area in the terminal identified at the terminal identification step requires updating, map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified at the terminal identification step; generating, if a program for updating the map data of the new map area in the terminal identified at the terminal identification step requires updating, program data for updating the program; creating distribution-purpose data that includes the map update data generated at the map update data generation step and the program data generated at the program data generation step; storing the distribution-purpose data created at the distribution-purpose data creation step; and distributing, if there is a distribution request from the terminal identified at the terminal identification step for map update data to update the map data of the standard update area that includes a saved location of the terminal, the distribution-purpose data stored at the data storage step to the terminal.

[0012] A computer program according to a third aspect of the present invention is a computer program installed in a computer that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal. The computer program is characterized by including the functions of: identifying, if new map data is registered, an area that is included in the registered new map data as a new map area; identifying a terminal in which the standard update area includes at least a portion of the new map area; generating, if a program for updating the map data of the new map area in the terminal identified by the terminal identification function requires updating, map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified by the terminal identification function; generating, if a program for updating the map data of the new map area in the terminal identified by the terminal identification function requires updating, program data for updating the program; creating distribution-purpose data that includes the map update data generated by the map update data generation function and the program data generated by the program data generation function; storing the distribution-purpose data created by the distribution-purpose data creation function; and distributing, if there is a distribution request from the terminal identified by the terminal identification function for map update data to update the map data of the standard update area that includes a saved location of the terminal, the distribution-purpose data stored by the data storage function to the terminal.

Effects of the Invention

[0013] The map distribution apparatus with the above constitution according to a first aspect of the present invention, if new map data is registered, can create and store in advance distribution-purpose data that includes map update data for updating the map data of an area with newly added map data and includes program data for executing in a terminal an update of map data based the map update data. It is thus possible to suppress the volume of distribution-purpose data created in advance and shorten the response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data. As a consequence, delays in the map data update processing can be suppressed especially during times of concentrated distribution requests from terminals.

[0014] The map distribution method according to a second aspect of the present invention, if new map data is registered, can create and store in advance distribution-purpose data that includes map update data for updating the map data of an area with newly added map data and includes program data for executing in a terminal an update of map data based the map update data. It is thus possible to suppress the volume of distribution-purpose data created in advance and shorten the response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data. As a consequence, delays in the map data update processing can be suppressed especially during times of concentrated distribution requests from terminals.

[0015] The computer program according to a third aspect of the present invention, if new map data is registered, can create and store in advance distribution-purpose data that includes map update data for updating the map data of an area with newly added map data and includes program data for executing in a terminal an update of map data based the map update data. It is thus possible to suppress the volume of distribution-purpose data created in advance and shorten the response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data. As a consequence, delays in the map data update processing can be suppressed especially during times of concentrated distribution requests from terminals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a schematic diagram that shows a map information distribution system according to an embodiment;

FIG. 2 is a block diagram that shows the structure of the map information distribution system according to the embodiment; FIG. 3 is an explanatory drawing of a version management system for basic map data stored in a center side map information database;

FIG. 4 is a drawing that shows a version management table stored in a version management database;

FIG. 5 is a drawing that shows an application management table stored in an application management database;

FIG. 6 is a drawing that describes an example of updating map data stored in a navigation device;

FIGS. 7 A and 7B are flowcharts of a specific distribution-purpose data creation processing program according to the embodiment; FIG. 8 is an explanatory drawing of a new map area;

FIG. 9 is an explanatory drawing of a pre-preparation determination area;

FIG. 10 is an explanatory drawing of an update target area; FIG. 11 is a flowchart of a distribution-purpose data distribution processing program according to the embodiment; and

FIG. 12 is a flowchart of a specific distribution-purpose data creation processing program according to another embodiment. BEST MODES FOR CARRYING OUT THE INVENTION [0017] A map distribution apparatus according to the present invention will be explained in detail below based on specific embodiments realized in a map distribution center 1 and with reference to the drawings. First, the schematic structure of a map information distribution system 2 that includes the map distribution center 1 according to the present embodiment will be described using FIG. 1. FIG. 1 is a schematic view that shows the map information distribution system 2 according to this embodiment.

[0018] As shown in FIG. 1, the map information distribution system 2 according to the present embodiment is basically constituted by the map distribution center 1, and a navigation device 4 installed in each vehicle 3. Note that an example according to this embodiment uses the navigation device 4 as a terminal that stores map data, and updates the stored map data based on data distributed from the map distribution center 1. However, a cellular telephone, PDA, personal computer, or the like may be used in place of the navigation device 4.

[0019] Here, the map distribution center 1 is a distribution center that generates data (to be referred to hereafter as map update data) for updating an old version of map data stored in the navigation device 4 to a new version of map data that reflects newly added and eliminated roads, facilities, and the like. The map distribution center 1 also generates application data, that is, program data required by the navigation device 4 for updating (reading, converting, and so on) map data based on the map update data. In addition, the map distribution center 1 distributes the generated map update data and application data. Note that two types of map update data exist, namely full update data for overwriting and updating all of the map data stored in the navigation device 4 (to be referred to hereafter as a full update), and differential update data for overwriting and updating only a specific area of the map data (to be referred to hereafter as a differential update), hi the embodiment to be described below, only the differential update data is used as map update data. [0020] The navigation device 4 is an on-vehicle device disposed in the vehicle 3, which travels roads throughout Japan, for displaying a map of the periphery of the vehicle position on the basis of the stored map data, and performing a route search and route guidance to a set destination. Here, the map distribution center 1 and the navigation device 4 are constituted to be capable of two-way communication using a vehicle communication module 5 (to be referred to simply as the communication module 5 hereafter) such as a cellular telephone or DCM installed in the vehicle in advance. Thus, various types of information, such as distribution request data described later and map update data, is transmitted and received between the map distribution center 1 and the navigation device 4.

When a specific condition is met (when the power is turned on, or a destination is set and route guidance started), the navigation device transmits to the map distribution center 1 a map update data distribution request in order to update the map data of a specific area (such as an 80-km² area centered on the user's home, or a 10-km² area centered on the set destination) to a new version of map data.

When the navigation device 4 receives the map update data from the map distribution center 1 in response to the transmitted distribution request, the navigation device 4 updates the stored map data on the basis of the transmitted map update data.

[0021] Next, the map distribution center 1 of the map information distribution system 2 will be described in detail using FIG. 2. FIG. 2 is a block diagram that shows the structure of the map information distribution system 2 according to the present embodiment. [0022] As shown in FIG. 2, the map distribution center 1 includes a server

(a new map area identification unit, a terminal identification unit, a map update data generation unit, an application data generation unit, a distribution-purpose data creation unit, a data storage unit, a data distribution unit, and a program version acquisition unit) 20, a center side map information database 26 serving as an information recording portion connected to the server 20, a version management database 27, a distribution-purpose data storage database 28, an application management database 33, and a center side communication device 29.

[0023] The server 20 is a control unit that performs overall control of the map distribution center 1, such as a process for registering new map data that incorporates the addition or elimination of roads and facilities throughout the country on the basis of an administrator's input operation or the like; a process for generating map update data to be distributed to the navigation device 4; a process for generating application data required by the navigation device 4 for updating (reading, converting, and so on) map data based on the map update data; a process for creating distribution-purpose data that includes the map update data and the required application data; and a process for distributing the created distribution-purpose data to the navigation device 4. The server 20 has a CPU 21 serving as a computational device and a control device for performing overall control of the server 20, a RAM 22 which is used as a working memory when the CPU 21 performs various types of computational processing, a ROM 23 storing control programs as well as a specific distribution-purpose data creation processing program (see FIGS. 7 A and 7B) and a distribution-purpose data distribution processing program (see FIG. 11), and an internal storage device such as a flash memory 24 for storing programs read from the ROM 23.

[0024] The center side map information database 26 is a storage unit that stores, by version and by area, basic map data 30 that is map data added on the basis of input data or an input operation from the outside and serves as a basis for updating the map data stored in the navigation device 4. Here, a version is creation time information for specifying the creation time of the map data, and by referencing the version, it is possible to specify the time at which the map data was created.

The map distribution center 1 manages versions of the basic map data 30 stored in the center side map information database 26 in units of two-dimensional (2D) 10-km² meshes. For example, FIG. 3 is an explanatory drawing of a version management system for the basic map data 30 stored in the center side map information database 26. As shown in FIG. 3, the basic map data 30 is managed by setting a mesh ID for every 2D mesh, and linking each mesh ID to the latest version number of the map data of the 2D mesh at the present time. In the example shown in FIG. 3, 5 is the latest version of the 2D mesh map data with the mesh ID 10001; 3 is the latest version of the 2D mesh map data with the mesh ID 10002; and 4 is the latest version of the 2D mesh map data with the mesh ID 10003. Regarding the basic map data 30, when the administrator registers new map data, the version of the 2D meshes included in the registered new map data is newly updated (e.g. version 4 is updated to version 5). Note that in addition to the latest version of the basic map data 30, the old version of the basic map data 30 is also stored in the center side map information database 26 by version and by 2D mesh.

[0025] The version management database 27 is a storage unit that stores a version management table 31, which shows the map data version currently stored in each navigation device 4 subject to distribution of the map update data. Here, the map data and the basic map data 30 stored in the navigation device 4 include a road network and various types of information required for route guidance and map display, and are constituted by map display data for displaying a map, intersection data relating to intersections, node data relating to node points, link data relating to roads (links), search data for finding a route, facility data relating to facilities, search data for finding a geographical location, and so on, for example.

The map information distribution system 2 manages versions of the map data stored in the navigation device 4 in units of 10-km² 2D meshes for every navigation device 4 that is a destination for distribution. FIG. 4 is a drawing that shows the version management table 31 stored in the version management database 27. As shown in FIG. 4, the version management table 31 manages by setting a user ID for every navigation device 4 subject to distribution of the map update data, setting a mesh ID for every 2D mesh, and linking the current version number of the map data to each user ID (a number with multiple digits) and each mesh ID. For the navigation device 4 with the user ID AOOl shown in FIG. 4, for example, 5 is the current version of the 2D mesh map data with the mesh ID 10001; 3 is the current version of the 2D mesh map data with the mesh ID 10002; and 4 is the current version of the 2D mesh map data with the mesh ID 10003. After distributing the map update data to the navigation device 4, the map distribution center 1 assumes that the navigation device 4, i.e., the distribution destination, performed map updating using the distributed map update data, and updates the version corresponding to the applicable user ID and mesh ID within the version management table 31.

[0026] The version management database 27 also stores position coordinates of the user's home as a saved location, which is registered in each navigation device 4 subject to distribution of the map update data (see FIG. 4). Note that although the user's home is designated as a saved location in this embodiment, any point may be used provided that the point is registered in advance in the navigation device 4. For example, the user's workplace or the like may be designated as a saved location. Further note that if a saved location is newly set in the navigation device 4, information regarding the set saved location is transmitted to the map distribution center 1, and the version management database 27 is updated.

[0027] The version management database 27 also stores the version number of the application currently installed in each navigation device 4 subject to distribution of the map update data (see FIG. 4). Based on the application version number in each navigation device 4 stored in the version management database 27, the map distribution center 1 determines whether to include application data in the distribution-purpose data. Note that when the application data is distributed as part of the distribution-purpose data, the version number of the application that corresponds to the navigation device 4, i.e., the distribution destination, stored in the version management database 27 is updated to the version of the distributed application data.

In addition, based on the application data included in pre-prepared distribution-purpose data (distribution-purpose data stored in the distribution-purpose data storage database 28), as shown in FIG. 4, the version management table 31 stores the application version of each navigation device 4 when updated, hi the example shown in FIG. 4, distribution-purpose data is pre-prepared for the navigation device with the user ID A002, and shows a case where the pre-prepared distribution-purpose data includes the application data that updates the application from version 4 to version 5.

[0028] The distribution-purpose data storage database 28 is a storage unit that stores distribution-purpose data 32 for distribution to the navigation device 4.

[0029] Here, the distribution-purpose data 32 is constituted from map update data, or from map update data and application data. The map update data is data that differentially updates the map data of an area (to be referred to hereafter as an update request area) as requested according to a distribution request from the navigation device 4, among the map data stored in the navigation device 4, to a new version of the map data. The map update data is generated by the server 20 based on the basic map data 30 and the version management table 31 stored in the version management database 27.

The application data is data for installing an application that is required for updating (reading, converting, and so on) the map data on the basis of the map update data received by the navigation device 4. Note that there are multiple versions of the application data, and the map update data that corresponds to each version (the map update data for which that application can execute an update) is determined in advance. More recently generated map update data is linked to a newer version of application data. [0030] After the map distribution center 1 receives a map update data distribution request from the navigation device 4, the map distribution center 1 generates the map update data to be distributed to the navigation device 4 that originated the distribution request. If the application version corresponding to the generated map update data is newer than the application version currently installed in the navigation device 4 that originated the distribution request, the corresponding application data is read from the application management database 33. Distribution-purpose data that includes the generated map update data and application data is subsequently distributed.

However, if the application version corresponding to the generated map update data is the same or older than the application version currently installed in the navigation device 4 that originated the distribution request, distribution-purpose data that only includes the generated map update data is distributed.

[0031] Thus, the application data is not included in the distribution-purpose data when distributing map update data to the navigation device 4 or the like that does not require a new application, such as map update data that updates areas other than those with newly registered map data. In other words, during the distribution-purpose data creation process as described above, the processing load of the map distribution apparatus is comparatively small, hi addition, there is little delay in the response time from reception of a distribution request from each navigation device 4 to distribution of the distribution-purpose data. Hence, only distribution-purpose data that includes application data of a large data size compared to the map update data is created and stored in advance. Consequently, the problems of the significant processing load on the map distribution apparatus and the increased storage area needed for storing the distribution-purpose data can both be eliminated.

Accordingly, in the case of distribution of the distribution-purpose data that includes application data to a specific navigation device 4, the map distribution center 1 creates the distribution-purpose data before the map update data distribution request is received from the specific navigation device 4, and stores the distribution-purpose data in the distribution-purpose data storage database 28. Once the map update data distribution request is subsequently received from the specific navigation device 4, the map distribution center 1 then reads the distribution-purpose data stored in the distribution-purpose data storage database 28 and distributes the read distribution-purpose data.

[0032] Note that the update request area for which the navigation device 4 requests the map update data varies depending on the circumstances of the navigation device 4 when the navigation device 4 requests the map update data. Specifically, the navigation device 4 is constituted so as to request the distribution of map update data from the map distribution center 1 when the ACC power is turned on and when a destination is set and route guidance started. When the ACC power of the navigation device 4 is turned on, the navigation device 4 requests distribution of the map update data for a 2D mesh that includes an area (standard update area) of a predetermined square distance (e.g. 80 km²) centered on a saved location in the navigation device 4 (such as the user's home), and a 2D mesh that includes all national high-standard roads (e.g. expressways and the like). When a destination is set and route guidance started by the navigation device 4, the navigation device 4 requests distribution of the map update data for a 2D mesh that includes an area of a predetermined square distance (e.g. 10 km²) centered on the set destination in the navigation device 4, and a 2D mesh that includes all national high-standard roads.

[0033] The application management database 33 is a storage unit that stores application data 34, and an application management table 35 that shows the correspondence relationships between the application data 34 and the map update data. Note that the application management database 33 stores all versions of the application data 34 generated by the map distribution center 1 up to the present.

The map information distribution system 2 manages the correspondence relationships between the application data 34 and the map update data in units of 10-km² 2D meshes. FIG. 5 is a drawing that shows the application management table 35 stored in the application management database 33. As shown in FIG. 5, the application management table 35 manages by linking, with respect to the mesh ID set for every 2D mesh of map data, the map data version numbers registered to each 2D mesh up to the present and the application data version numbers corresponding to the map data version updates of each 2D mesh. In the example shown in FIG. 5, the 2D mesh with the mesh ID 10001 has map data versions 1 to 5. In order to update from version 1 to version 2, the application version 1 must be installed in the navigation device 4; to update from version 1 or 2 to version 3, the application version 2 must be installed in the navigation device 4; to update from any one of versions 1, 2 or 3 to version 4, the application version 3 must be installed in the navigation device 4; and to update from any one of versions 1, 2, 3 or 4 to version 5, the application version 4 must be installed in the navigation device 4. As an example, the application version currently installed in the navigation device 4 is version 3, however, the map update data that updates the map data version of the 2D mesh with the mesh ID 10001 from 4 to 5 is to be distributed from the map distribution center 1 to the navigation device. Therefore, version 4 of the application data 34 is distributed together with the map update data as the distribution-purpose data. Note that when navigation devices 4 of a plurality of formats are included as navigation devices 4 to which the map update data is distributed, the map distribution center 1 manages applications by creating the application management table 35 for every format.

[0034] The center side communication device 29 serves as a communication device for communicating with the navigation device 4 via a network 8. Here, a communication system such as a LAN (Local Area Network), a WAN (Wide Area Network), the intranet, a cellular telephone network, a telephone network, a public communication network, a private communication network, the Internet, or another communication network, for example, may be used as the network 8. A communication system employing satellite CS broadcasting, BS broadcasting, digital terrestrial broadcasting, FM multiplex broadcasting, and so on may also be used. Furthermore, a communication system used in an intelligent transport system (ITS), such as an electric toll collection (ETC) and a dedicated short range communications (DSRC), may also be used. [0035] A brief example of updating the map data stored in the navigation device 4 will be explained next using FIG. 6. In the example shown in FIG. 6, a map update data distribution request to update the map data of a predetermined update request area has been transmitted from the navigation device 4 to the map distribution center 1. Among map data 36 stored in the navigation device 4, the version of the mesh to be updated in the update request area is 4, and the version of the application installed in the navigation device 4 is 3. Meanwhile, the latest version of the update request area in the basic map data 30 of the map distribution center 1 is 5; and the application version required for updating the map data of the update-targeted mesh to version 5 is 4.

In this case, the map distribution center 1 generates the map update data by comparing the versions 4 and 5 of the basic map data 30 stored in the center side map information database 26. Note that the map update data generated in such case is data that, among the map data 36 stored in the navigation device 4, updates the map data of the update-targeted mesh in the update request area from version 4 to version 5. When generating the map update data, a process (network confirmation process) that confirms whether the road network after updating is correctly connected between the area whose map data was updated and adjacent areas is also performed.

The navigation device 4 is installed with version 3 of the application. Therefore, in order to update the application version installed in the navigation device 4 to version 4, the map distribution center 1 reads version 4 of the application data from the application management database 33. The map distribution center 1 next creates the distribution-purpose data that includes the generated map update data and version 4 of the application data read from the application management database 33. When creating the distribution-purpose data, a process (error check process) that checks for errors in the created distribution-purpose data is also performed. However, the specific distribution-purpose data that is distributed to a specific navigation device as described later is created before a distribution request is received from the specific navigation device 4. hi addition, the process to read the application data and the error check process that accompany creation of the distribution-purpose data are executed before a distribution request is received from the specific navigation device 4.

The map distribution center 1 then distributes the created distribution-purpose data to the navigation device 4 that originated the distribution request. Meanwhile, the navigation device 4 that received the distribution-purpose data first upgrades the version of the installed application based on the application data 34 included in the received distribution-purpose data. Consequently, the version of the application installed in the navigation device 4 is updated from version 3 to version 4. Next, the map data 36 is updated using the map update data included in the same received distribution-purpose data. Consequently, among the map data 36 stored in the navigation device 4, the map data of the update-targeted mesh in the update request area is updated from version 4 to version 5.

[0036] Next, a specific distribution-purpose data creation processing program executed by the server 20 of the map distribution center 1 in the map information distribution system 2 according to the present embodiment will be described based on FIGS. 7A and 7B. FIGS. 7A and 7B are flowcharts of the specific distribution-purpose data creation processing program according to this embodiment. Here, the specific distribution-purpose data creation processing program is executed when a registration operation of new map data is performed in the map distribution center 1, and is a program that creates the specific distribution-purpose data to be distributed to a specific navigation device before a distribution request is received from the specific navigation device 4. Note that the program below shown in the flowcharts of FIGS. 7 A and 7B is stored in the RAM 22 and the ROM 23 provided in the server 20, and executed by the CPU 21. [0037] In the specific distribution-purpose data creation processing program, first, the CPU 21 at step (abbreviated to "S" below) 1 performs a new map data registration process based on data input by an administrator. Namely, if a road or facility anywhere in the country is newly established or eliminated, a registration process is performed in which map data that incorporates such modification content is generated as a new version of the basic map data 30, and stored in the center side map information database 26. The registration of new map data at S 1 is performed in units of 2D meshes. In other words, if a road or facility anywhere in the country is newly established or eliminated, only the map data of 2D meshes that incorporate such modified locations is registered as new map data. Accordingly, the basic map data 30 is managed by version in units of 2D meshes (see FIG. 3).

Further note that the registration of new map data may be performed in units of areas other than 2D meshes. For example, the registration of new map data may be performed in units of administrative areas such as cities, wards, towns, or villages, or areas smaller than the 2D mesh (e.g. a 2.5-km² area).

[0038] Next, at S2, the CPU 21 generates the application data that corresponds to the map update data for incorporating the new map data registered at Sl (i.e., the application required by the navigation device 4 to update (read, convert, and so on) the map update data for incorporating the new map data). The generated application data is linked to a new version number and stored in the application management database 33. The application management table 35 (FIG. 5) is also updated. Note that if the corresponding application data is already stored in the application management database 33, the process at S2 is not executed. [0039] Next, at S3, the CPU 21 performs a new map area identification process that identifies a new map area whose version of the basic map data 30 has been updated by the registration of new map data (for which new map data has been registered). It should be noted that, if the new map data registered at Sl is data that encompasses a plurality of 2D meshes (e.g. if a new road crosses a plurality of 2D meshes), the new map area identification process identifies an area that combines the plurality of 2D meshes which include the new map data as a new map area. For example, a new road 41 as shown in FIG. 8 runs through three 2D meshes 42 to 44. Therefore, an area that combines the 2D meshes 42 to 44 is identified as a new map area. Further note that, if the new map data registered at Sl is data that does not encompass a plurality of 2D meshes (e.g. if a new road is contained in one 2D mesh), only that particular 2D mesh is identified as a new map area.

[0040] At S4, the CPU 21 sets a pre-preparation determination area based on the new map area identified at S2. Here, the pre-preparation determination area is of a range enclosed by a border that connects points 40 km away from the new map area identified at S3. The pre-preparation determination area is used to identify the navigation device 4 for which map update data is to be generated before an update request is received at S4.

FIG. 9 is a drawing that shows a pre-preparation determination area 45 that is set when an area combining the 2D meshes 42 to 44 shown in FIG. 8 is identified as the new map area. As shown in FIG. 9, the pre-preparation determination area 45 is of a range enclosed by a border that connects points 40 km away from the 2D meshes 42 to 44. Specifically, a 40-km² square surrounds the periphery of the 2D meshes 42 to 44 while contacting the 2D meshes 42 to 44, and the pre-preparation determination area 45 is set within the range of an outer perimeter drawn by the square.

Once the pre-preparation determination area is set at S4, information that identifies the pre-preparation determination area (e.g. coordinates of the area outer perimeter and so on) is stored in the RAM 22 or the like.

[0041] At S5, the CPU 21 subsequently identifies a navigation device for which the distribution-purpose data is created before reception of an update request (to be referred to hereafter as a pre-preparation target navigation device). Namely, the position coordinates of the user's homes are first acquired from the version management database 27 as saved locations that are registered in the navigation devices 4 subject to distribution of the distribution-purpose data. The CPU 21 then compares the position coordinates of the user's homes and the pre-preparation determination area set at S4, and identifies the navigation devices 4 in which the position coordinates of the user's home are inside the pre-preparation determination area. Note that the navigation device 4 in which the position coordinates of the user's home are included inside the pre-preparation determination area is a navigation device wherein at least a portion of the new map area is included within a standard update area (a 2D mesh that contains an 80-km area centered on a saved location (the user's home) of the navigation device 4) of that particular navigation device 4. In other words, the pre-preparation target navigation device is a navigation device in which the map data of at least a portion of the new map area is subject to updating when the ACC power is turned on and the map data of the standard update area is updated.

[0042] At S6, the CPU 21 determines whether at least one of the navigation devices at S4 has been identified as a pre-preparation target navigation device. If, as a result, it is determined that at least one of the navigation devices 4 has been identified as a pre-preparation target navigation device (S6: YES), the routine proceeds to S7. However, if it is determined that none of the navigation devices 4 has been identified as a pre-preparation target navigation device (S6: NO), the pre-preparation of distribution-purpose data is not performed and the specific distribution-purpose data creation processing program is ended.

[0043] The processes at S7 to S16 below are executed for each pre-preparation target navigation device identified at S4. Specifically, the processes at S7 to S 16 are repeatedly executed in order from the pre-preparation target navigation device with the smallest user ID. After the processes for all the identified pre-preparation target navigation devices are complete, the specific distribution-purpose data creation processing program is ended. [0044] First, at S7, the CPU 21 refers to the version management table 31

(FIG. 4) and the application management table 35 (FIG. 5), and determines whether the application required for updating the map data of the new map area identified at S3 is already installed in the pre-preparation target navigation device 4 undergoing processing. [0045] If it is determined that the application required for updating the map data of the new map area is already installed (S7: YES), the process is ended without pre-preparing the distribution-purpose data for the pre-preparation target navigation device 4 currently undergoing processing. However, if it is determined that the application required for updating the map data of the new map area is not installed (S7: NO), the routine proceeds to S8.

For example, if the new map data registered at Sl is version 5 of the map data with the mesh ID 10001, the application required for updating the map data of the new map area is application version 4.

[0046] At S8, the CPU 21 refers to the version management table 31 (FIG. 4) and the application management table 35 (FIG. 5), and determines whether the distribution-purpose data, which is intended for distribution to the pre-preparation target navigation device 4 undergoing processing and includes the application data required for updating the map data of the new map area identified at S3, is already pre-prepared in the distribution-purpose data storage database 28. Namely, if the distribution-purpose data that is intended for distribution to the pre-preparation target navigation device 4 undergoing processing is stored in the distribution-purpose data storage database 28, and the application data included in the distribution-purpose data is the application data for updating to the application version required for updating the map data of the new map area identified at S3, then YES is determined at S8. However, if the distribution-purpose data that is intended for distribution to the pre-preparation target navigation device 4 undergoing processing is not stored in the distribution-purpose data storage database 28, and the application data included in the distribution-purpose data even if stored is not the application data for updating to the application version required for updating the map data of the new map area identified at S3, then NO is determined at S8.

[0047] If it is determined that the application data required for updating the map data of the new map area is not pre-prepared in the distribution-purpose data storage database (S 8: NO), the routine proceeds to S9. However, if it is determined that the application data required for updating the map data of the new map area is pre-prepared in the distribution-purpose data storage database (S8: YES), the routine proceeds to S 13.

[0048] At S9, the CPU 21 sets an update target area that includes the standard update area of the pre-preparation target navigation device undergoing processing (a 2D mesh that includes an 80-km² area centered on a saved location (the user's home) in the navigation device) and the new map area identified at S3, and generates the map update data for updating the map data of the update target area. Specifically, the CPU 21 first acquires the version of the update target area in the applicable navigation device 4 from the version management database 27. The CPU 21 then compares the acquired version of the basic map data 30 and the latest version of the basic data 30 for the same area, and generates the map update data. Note that the map update data generated in such case is data that, among the map data stored in the navigation device 4, updates the map data of the update-targeted mesh in the update request area from the current version to the latest version (see FIG. 6). At S9, when generating the map update data, the CPU 21 also performs the network confirmation process that confirms whether the road network is correctly connected between the update target area after updating and areas adjacent to the update target area. [0049] FIG. 10 is a drawing that shows an update target area 48 that is set for a pre-preparation target navigation device in which an area that combines the 2D meshes 42 to 44 shown in FIG. 8 is identified as the new map area and in which there is a saved location (the user's home) within the pre-preparation determination area 45 shown in FIG. 9. As shown in FIG. 10, the update target area 48 is an area that includes a standard update area 49 of the pre-preparation target navigation device (a 2D mesh that includes an 80-km² area centered on a saved location (the user's home) in the navigation device) and the 2D meshes 42 to 44, which are the new map area. [0050] At SlO, the CPU 21 refers to the application management table 35

(FIG. 5), and reads from the application management database 33 the application data for updating the application version currently installed in the pre-preparation target navigation device undergoing processing to the application version required for updating the map data of the new map area identified at S3.

[0051] Next, at Sl 1, the CPU 21 creates the distribution-purpose data that includes the map update data generated at S9 and the application data read at SlO. In addition, the error check process that checks whether the distribution-purpose data created at S 11 has any errors is performed. [0052] At S 12, the CPU 21 subsequently links the distribution-purpose data created at SIl to the user ID of the navigation device, i.e., the distribution destination, and stores the data in the distribution-purpose data storage database 28. Based on the distribution-purpose data stored in the distribution-purpose data storage database 28, the version management table 31 (FIG. 4) is updated. Specifically, an update is performed of information that identifies the application version of the navigation device 4 when updated by the application data included in the current pre-prepared distribution-purpose data. Note that if a distribution request is received from the navigation device 4 for which distribution-purpose data has been pre-prepared as described later, the distribution-purpose data stored in the distribution-purpose data storage database 28 is distributed in response to the received distribution request (S26).

[0053] Meanwhile, at S 13, the CPU 21 sets an update target area that includes the standard update area of the pre-preparation target navigation device undergoing processing and the new map area identified at S3, and generates the map update data for updating the map data of the update target area. The specific processing content is identical to that at S9 and therefore not explained here.

[0054] Next, at S 14, the CPU 21 reads the distribution-purpose data that corresponds to the generated map update data from among the distribution-purpose data stored in the distribution-purpose data storage database 28. Note that the distribution-purpose data that corresponds to the generated map update data is intended for distribution to the pre-preparation target navigation device 4 undergoing processing, and includes the application data required for updating the map data of the new map area identified at S3. [0055] At S 15, the CPU 21 subsequently adds the map update data generated at S 13 to the distribution-purpose data read from the distribution-purpose data storage database 28 at S 14, and sets the distribution-purpose data with the added map update data as new distribution-purpose data. [0056] At S 16, the CPU 21 stores the distribution-purpose data with the map update data added at Sl 5 in the distribution-purpose data storage database 28.

After the processes at S7 to S 16 above are completed for all the pre-preparation target navigation devices, the specific distribution-purpose data creation processing program is ended. [0057] Next, a map data distribution processing program executed by the server 20 of the map distribution center 1 in the map information distribution system 2 according to the present embodiment will be described based on FIG. 11. FIG. 11 is a flowchart of the map data distribution processing program according to this embodiment. The map data distribution processing program is executed after a map update data distribution request is received from the navigation device 4, and distributes map update data in response to the distribution request transmitted from the navigation device 4. Note that the program below shown in the flowchart of FIG. 11 is stored in the RAM 22 and the ROM 23 provided in the server 20, and executed by the CPU 21. [0058] According to the map update data distribution processing program, first, at S21, the CPU 21 receives the map update data distribution request transmitted from the navigation device 4. Information relating to the received distribution request is stored in the RAM 22.

[0059] Note that the distribution request includes the user ID identifying the navigation device 4 that transmitted the distribution request, and information identifying the area for which an update is requested. In this case, the navigation device 4 is constituted so as to request the distribution of map update data from the map distribution center 1 when the ACC power is turned on and when a destination is set and route guidance started. When the ACC power of the navigation device 4 is turned on, the area for which an update is requested is a 2D mesh that includes an area (standard update area) of a predetermined square distance (e.g. 80 km²) centered on a saved location in the navigation device 4, and a 2D mesh that includes all national high-standard roads (e.g. expressways and the like). Alternatively, when a destination is set and route guidance started by the navigation device 4, the area for which an update is requested is a 2D mesh that includes an area of a predetermined square distance (e.g. 10 km²) centered on the set destination in the navigation device 4, and a 2D mesh that includes all national high-standard roads. [0060] Next, at S22, the CPU 21 determines whether the navigation device 4 that originated the distribution request is a navigation device for which the distribution-purpose data has been pre-prepared at S 8 to S 12. If it is determined that the navigation device 4 that originated the distribution request is a navigation device for which the distribution-purpose data has been pre-prepared (S22: YES), the routine proceeds to S23. However, if it is determined that the navigation device 4 that originated the distribution request is not a navigation device for which the distribution-purpose data has been pre-prepared (S22: NO), the routine proceeds to S25.

[0061] At S23, the CPU 21 determines whether the distribution request received from the navigation device 4 is a map update data distribution request for updating the map data of an area that includes the standard update area. Note that according to the present embodiment, a distribution request transmitted when the ACC power of the navigation device 4 is turned on is a map update data distribution request for updating the map data of an area that includes the standard update area. [0062] If it is determined that the distribution request received from the navigation device 4 is a map update data distribution request for updating the map data of an area that includes the standard update area (S23: YES), the routine proceeds to S24. However, if it is determined that the distribution request received from the navigation device 4 is not a map update data distribution request for updating the map data of an area that includes the standard update area (S23: NO), the routine proceeds to S25.

[0063] At S24, the CPU 21 reads the distribution-purpose data corresponding to the navigation device 4 that transmitted the distribution request from among the distribution-purpose data stored in the distribution-purpose data storage database 28 at S12. The CPU 21 subsequently distributes the read distribution-purpose data to the navigation device 4 that transmitted the distribution request (S26). The navigation device 4 that received the distribution-purpose data then updates the map data stored in the navigation device 4 and the application installed in the navigation device 4, based on the received distribution-purpose data. Consequently, based on the application data included in the distribution-purpose data, the application installed in the navigation device 4 is first updated. Next, among the map data stored in the navigation device 4, the map data of the update-targeted mesh in the update request area is updated to the new version of map data, based on the map update data included in the distribution-purpose data. If application data is not included in the distribution-purpose data, only the map data is updated.

If new map data is registered that changes (newly establishes or eliminates) a national high-standard road (e.g. an expressway or the like) since the map update data was previously distributed to the navigation device 4 that transmitted the distribution request, the map update data for updating the 2D mesh which includes that particular high-standard road is also generated and included for distribution in the distribution-purpose data. [0064] Meanwhile, at S25, based on the distribution request, the CPU 21 creates the distribution-purpose data that includes the map update data for updating the map data of the requested area to the new version of map data, and the required application data. However, if the required application data is already installed in the navigation device that originated the request, the distribution-purpose data is created from only the generated map update data. The CPU 21 subsequently distributes the created distribution-purpose data to the navigation device 4 that transmitted the distribution request (S26). Note that when creating the distribution-purpose data at S25, the process that reads the application data corresponding to the map update data from a database or the like and the process that checks for errors in the created distribution-purpose data are also performed similar to related art. Further note that the distribution-purpose data creation method at S25 is already known and therefore not explained here. Based on the distribution-purpose data distribution process (S26), the version management table 31 (FIG. 4) stored in the version management database 27 is updated. [0065] As explained in detail above, in the map distribution center 1, a map update method used by the map distribution center 1 , and a computer program executed by the map distribution center 1 of the present embodiment, if new map data is registered, the 2D mesh that includes the new map data is identified as a new map area (S3). Based on the identified new map area and the saved location information in each navigation device 4, pre-preparation target navigation devices 4 are identified for which the map update data is generated before an update request is received (S5). If the application required for updating the map data of the new map area is not installed in the pre-preparation target navigation device 4, the distribution-purpose data that includes the map update data and the required application data to be distributed to the navigation device is created before a distribution request is received (SIl), and stored in the distribution-purpose storage database 28 (S 12). Therefore, the volume of distribution-purpose data created in advance can be suppressed, and the response time from reception of a distribution request from each terminal to distribution of the distribution-purpose data can be shortened. As a consequence, delays in the map data update processing can be suppressed especially during times of concentrated distribution requests from terminals. In addition, the corresponding application data is included in the distribution-purpose data only when the version of the program required by the navigation device 4 for updating the map data based on the map update data to be distributed is newer than the version of the application installed in the navigation device 4, i.e., the distribution destination. Therefore, the data size of the distribution-purpose data can be reduced.

[0066] Note that the present invention is not limited to the embodiment described above, and may of course be subjected to various improvements and modifications within a scope that does not depart from the spirit of the present invention. For example, according to the present embodiment, distribution-purpose data is created for every pre-preparation target navigation device 4 and stored in a database. However, common distribution-purpose data that can be distributed to a plurality of navigation devices 4 may be created. An example is explained in detail below. [0067] FIG. 12 is a flowchart of a specific distribution-purpose data creation processing program according to another embodiment.

Note that the processes at SlOl to S 106 are identical to the processes at Sl to S6 of the specific distribution-purpose data creation processing program according to the embodiment shown in FIGS. 7 A and 7B, and therefore not described here.

[0068] At S 107, the CPU 21 identifies the application data that must be distributed to each pre-preparation target navigation device identified at S 104. For example, if the pre-preparation target navigation device is currently installed with version 3 and the application version 5 is required for updating the map data of the new map area, the application data is identified for updating the application from version 3 to version 5. The CPU 21 then turns on a flag that corresponds to the application data identified for every pre-preparation target navigation device. For example, when application data has been identified for updating the application from version 1 to version 5, a flag 1 is turned on. When application data has been identified for updating the application from version 2 to version 5, a flag 2 is turned on. When application data has been identified for updating the application from version 3 to version 5, a flag 3 is turned on. When application data has been identified for updating the application from version 4 to version 5, a flag 4 is turned on. Note that for a pre-preparation target navigation device that is already installed with the application required for updating the map data of the new map area, the process is ended without turning on any of the flags.

[0069] Next, at S 108, the CPU 21 sets an update target area that includes the standard update area of all the pre-preparation target navigation devices for which flags were turned on at S 107 (a 2D mesh that includes an 80-km² area centered on a saved location (the user's home) in the navigation device) and the new map area identified at S 103, and generates the map update data for updating the map data of the update target area. [0070] At S 109, the CPU 21 reads from the application management database 33 the application data that corresponds to the flags turned on at S 107 (e.g. if the flags 3 and 4 are turned on, the application data for updating the application from version 3 to version 5 and the application data for updating the application from version 4 to version 5). [0071] Next, at SIlO, the CPU 21 creates, for every flag, the distribution-purpose data that includes the map update data generated at S 108 and the application data read at S 109. In addition, the error check process that checks whether the distribution-purpose data created at SUO has any errors is performed. [0072] At Sill, the CPU 21 subsequently links the distribution-purpose data created at SIlO to the flags, and stores the data in the distribution-purpose data storage database 28. Note that if a distribution request is received from a navigation device 4 for which any of the flags is turned on, the distribution-purpose data stored in the distribution-purpose data storage database 28 corresponding to the turned-on flag is distributed in response to the distribution request.

[0073] Note that an example according to this embodiment uses the navigation device 4 as a terminal that updates stored map data based on data distributed from the map distribution center 1. However, a cellular telephone, PDA, personal computer, or the like may be used in place of the navigation device 4.

[0074] The size of the pre-preparation determination area set at S4 and S 104 may be modified depending on the density of saved locations. For example, in an area with a high density of saved locations, the pre-preparation determination area may be set narrower than normal (40 km around the new map area), and in an area with a low density of saved locations, the pre-preparation determination area may be set wider than normal. Accordingly, the volume of pre-prepared distribution-purpose data can be set to an appropriate size.

[0075] Further, according to the present embodiment, at S 108, the CPU 21 sets the update target area as an area (see FIG. 10) that includes the standard update area of the navigation device 4 (a 2D mesh that includes an 80-km² area centered on a saved location (the user's home) in the navigation device) and the new map area identified at S2. However, the target update area may be set to an area that includes the standard update area and a pre-preparation target area.

Claims

1. A map distribution apparatus that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal, the map distribution apparatus characterized by comprising: a new map area identification unit that, if new map data is registered, identifies an area that is included in the registered new map data as a new map area; a terminal identification unit that identifies a terminal in which the standard update area includes at least a portion of the new map area; a map update data generation unit that, if a program for updating the map data of the new map area in the terminal identified by the terminal identification unit requires updating, generates map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified by the terminal identification unit; a program data generation unit that, if a program for updating the map data of the new map area in the terminal identified by the terminal identification unit requires updating, generates program data for updating the program; a distribution-purpose data creation unit that creates distribution-purpose data that includes the map update data generated by the map update data generation unit and the program data generated by the program data generation unit; a data storage unit that stores the distribution-purpose data created by the distribution-purpose data creation unit; and a data distribution unit that, if there is a distribution request from the terminal identified by the terminal identification unit for map update data to update the map data of the standard update area that includes a saved location of the terminal, distributes the distribution-purpose data stored by the data storage unit to the terminal.

2. A map distribution method that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal, the map distribution method characterized by comprising the steps of: identifying, if new map data is registered, an area that is included in the registered new map data as a new map area; identifying a terminal in which the standard update area includes at least a portion of the new map area; generating, if a program for updating the map data of the new map area in the terminal identified at the terminal identification step requires updating, map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified at the terminal identification step; generating, if a program for updating the map data of the new map area in the terminal identified at the terminal identification step requires updating, program data for updating the program; creating distribution-purpose data that includes the map update data generated at the map update data generation step and the program data generated at the program data generation step; storing the distribution-purpose data created at the distribution-purpose data creation step; and distributing, if there is a distribution request from the terminal identified at the terminal identification step for map update data to update the map data of the standard update area that includes a saved location of the terminal, the distribution-purpose data stored at the data storage step to the terminal.

3. A computer program installed in a computer that, if there is a distribution request from a terminal for map update data to update map data of a standard update area that includes a saved location of the terminal among map data stored in the terminal, distributes the map update data in response to the distribution request from the terminal, the computer program characterized by comprising the functions of: identifying, if new map data is registered, an area that is included in the registered new map data as a new map area; identifying a terminal in which the standard update area includes at least a portion of the new map area; generating, if a program for updating the map data of the new map area in the terminal identified by the terminal identification function requires updating, map update data for updating the map data of an update target area that includes the new map area and the standard update area, among the map data stored in the terminal identified by the terminal identification function; generating, if a program for updating the map data of the new map area in the terminal identified by the terminal identification function requires updating, program data for updating the program; creating distribution-purpose data that includes the map update data generated by the map update data generation function and the program data generated by the program data generation function; storing the distribution-purpose data created by the distribution-purpose data creation function; and distributing, if there is a distribution request from the terminal identified by the terminal identification function for map update data to update the map data of the standard update area that includes a saved location of the terminal, the distribution-purpose data stored by the data storage function to the terminal.